Article

Incorporation of dietary n-3 fatty acids into ovarian compartments in dairy cows and the effects on hormonal and behavioral patterns around estrus

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Abstract

The objective of this study was to examine the incorporation of dietary n-3 fatty acids (FAs) into ovarian compartments and the effects on hormonal and behavioral patterns around estrus. Multiparous 256-day pregnant cows were fed either a standard diet both prepartum and postpartum (PP) (control; n=22) or supplemented with extruded flaxseed (E-FLAX) providing C18:3n-3 at 172.2 and 402.5  g/day per cow prepartum and PP respectively (n=22). The estrous cycle was synchronized, and at day 7 of the cycle, the cows were injected with prostaglandin F(2)(α) (PGF(2)(α)) and then subjected to 5 days of intensive examination. Compared with those in the control, in the E-FLAX group, the interval from PGF(2)(α) injection to behavioral estrus peak tended to be longer (3.6  h; P<0.1), that to estradiol (E(2)) peak was 6.5  h longer (P<0.03), and that to LH peak tended to be longer (5.3  h; P<0.07). The durations of behavioral estrus and E(2) surge were longer, and the area under the E(2) curve was greater in the E-FLAX cows. Afterward, 7-8 days following behavioral estrus, follicular fluids (FFs) from >7  mm follicles were aspirated. The proportions of n-3 FA increased in plasma, FF, and granulosa cells in the E-FLAX group. The concentrations of PGE(2) in the E(2)-active follicles tended to be lower in the E-FLAX cows (P<0.06). In conclusion, several modifications in hormonal and behavioral estrus patterns were demonstrated in cows fed n-3 FA, which might be attributed to alterations in membrane FA composition and partly mediated by lower PGE(2) synthesis.

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... Research in our laboratory has demonstrated the beneficial effects of n-3 FA supplementation on the reproductive system in dairy cows (Zachut et al., 2010b(Zachut et al., , 2011Moallem et al., 2013) and bulls (Moallem et al., 2015), as confirmed in other reports. Feeding n-3 FA attenuated endometrial PGF 2α (Mattos et al., 2004), and cows fed rolled flaxseed exhibited decreased pregnancy loss rates and larger ovulatory follicles (Ambrose et al., 2006). ...
... The effect of feeding EF on FA composition of granulosa cells has only been determined in a small number of studies. In Zachut et al. (2011), cows were fed EF at a rate of 9.2% of DM and the composition of the FA in granulosa cells obtained from E 2 -active follicles aspirated in vivo was determined. The proportion of ALA was 4.5 times higher and that of C20: 4n -3 was 6 times higher in cows supplemented with EF compared with controls. ...
... The proportion of ALA was 4.5 times higher and that of C20: 4n -3 was 6 times higher in cows supplemented with EF compared with controls. The proportion of EPA was also higher in the EF-fed cows, and the proportions of DPAn-3 and DHA were numerically but not significantly higher in the EF-fed versus control cows (Zachut et al., 2011). The total n-3 FA content increased from 1.6% in the controls to 7.8% in the EF-fed cows, and the n -6: n -3 ratios were 29.0 and 5.2, respectively. ...
Article
Mammals can synthesize all of the fatty acids (FA) necessary for proper health and functioning with the exception of FA in the n-3 (omega-3) and n-6 (omega-6) families of polyunsaturated fatty acids (PUFA), which should be supplied in the diet. The PUFA are the predominant type of lipid in dairy cattle diets; however, common feedstuffs are rich in n-6 FA, whereas the supply of n-3 FA in the intensive dairy industry is mainly limited to flaxseed and fish oils. The n-3 FA are involved in many biological systems and processes, and therefore their dietary supplementation is of special interest in dairy cattle. Furthermore, because milk, milk products, and meat are among the most important and widely used components in traditional and modern human diets, enrichment of these food products with n-3 FA is of special importance. The purpose of this review is to provide a comprehensive description of different aspects and outcomes involved in dietary n-3 FA supplementation in dairy cattle. I provide an inclusive review of the effects of n-3 FA on milk and milk solids and the FA profile in milk fat upon feeding a variety of flaxseed products or fish oil. Selective uptake of n-3 FA has been demonstrated in the ovary compartments, as well as in bull sperm and in the unborn calf through the placenta. Incorporation of these unique FA into the reproductive system influences many processes and exerts some positive effects on fertility. In addition, beneficial effects of feeding n-3 FA on the reproductive system of females and males can be achieved with supplementation of α-linolenic acid from flaxseed or from eicosapentaenoic and docosahexaenoic acids from fish oil. This work provides a broad perspective and demonstrates the importance and potential of n-3 FA dietary supplementation in dairy cattle on the animal itself, as well as its secondary effects, which are associated with human nutrition and health.
... that large amounts of dietary ALA were effectively transferred into the plasma and that the incorporation rate was proportional to the amount consumed (Zachut et al. 2011). There was also slightly more plasma ALA in the FO group than in the SFA one, most likely because of the small amount of ALA provided by the FO supplement. ...
... Also, the proportion of DHA was dramatically increased in plasma of the FO cows, which indicates successful transfer of this important FA from the diet into the blood. In general, the profile of FAs in FF was very similar to that in plasma, as was also reported in other studies (Zeron et al. 2002, Zachut et al. 2011. This indicates that there is relatively free passage of plasma components into the FF, which is a crucial condition for altering ovarian activity and oocyte environment by absorption of blood factors exclusively from dietary supplementation. ...
... In this study, no differences between treatments were observed in preovulatory follicle characteristics, as was also found by Zachut et al. (2011). In another study, Ambrose et al. (2006) found that the diameter of ovulatory follicles was increased in cows fed flaxseed, which was not found in this study, by Mendoza et al. (2011) in grazing cows fed FO, or by Bilby et al. (2006) in lactating dairy cows. ...
Article
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The objectives were to determine the differential incorporation of various omega-3 (n-3) fatty acids (FAs) supplemented to dairy cows into ovarian compartments, and assess the effects on in vitro fertilization (IVF). Forty-two 256-day-pregnant cows were supplemented with encapsulated fats, in treatments designated as: (i) SFA - saturated fat at 240 and 560 g/d per cow, prepartum and postpartum, respectively; (ii) FLX - flaxseed oil at 300 and 700 g/d per cow prepartum and postpartum, respectively; (iii) FO - fish oil at 300 and 700 g/d per cow prepartum and postpartum, respectively. Commencing at 60 days in lactation ovum pickup (OPU) was performed twice weekly (20 sessions; 5 cows per group) and in vitro maturation and fertilization were conducted. The proportion of ALA was greater in follicular fluid (FF), granulosa cells and cumulus-oocyte-complexes (COCs) of FLX cows than in other groups (P < 0.001). The proportion of DHA was 6.7 times as great in FF of FO as in other groups (P < 0.001); DPAn-3 and DHA were detected in COCs of FO but not in others. The follicles number during OPU was higher in FLX and FO than in SFA (P < 0.05), and the oocyte cleavage rate was higher in FLX and FO than in SFA (P < 0.01). Also, the percentage of oocytes that developed to blastocysts tended to be higher in both n-3 groups than in SFA (P < 0.1). In conclusion, both dietary n-3 FAs similarly improved folliculogenesis and IVF performance, therefore ALA-rich botanical n-3 seem to be a satisfactory approach to improve oocyte quality.
... Similar effects on VFA production and molar proportions have been observed by Getachew et al. (2001), Jalc et al. (2006Jalc et al. ( , 2007 and Toral et al. (2009). Zachut et al (2011) reported that dry mater intake from pre-partum not affected, however the postpartum dry mater intake was higher in cows treated flaxseed than control. Also, milk yield was 6.4% higher in flaxseed than in control, and fat content was 0.4 unit lower in flaxseed cows than in control. ...
... Feed intake reflect the variation in TDN and DCP values presented in Table (4). The results are in agreement with those observed by Zachut et al (2011) who reported that dry mater intake from pre-partum not affected, however the postpartum dry mater intake was higher in cows with treated flaxseed oil than control. Also, milk yield was 6.4% higher in flaxseed than in control, and fat content was 0.4 unit lower in flaxseed cows than in control. ...
... Moallem (2009) reported that the average daily milk production was 1.2 kg (2.7%) higher in the dairy cows supplemented with extruded linseed at 40 g/kg DM compared to the control diet. Zachut et al. (2011) who found that milk yield was 6.4% higher in flaxseed than in control, and fat content was 0.4 unit lower in flaxseed cows than in control. Ambrose et al. (2006) reported that higher alfalinolinc acid by 187% in cows fed flaxseed oil than cows fed control. ...
... Peripartum supplementation of n-3 rich linseed diet numerically increased the onset of PGF 2α induced oestrus by 3.6 h (P=0.1) postpartum and the plasma LH and E 2 peak were longer (6.5 h and 5.3 h, respectively) in other study by the same group (Zachut et al., 2011). ...
... The mean oestrus duration did not differ signifi cantly (P>0.05) in both the groups (Table 2). Contrary to our fi nding, Zachut et al. (2011) observed that the duration of behavioral oestrus was longer in the fl axseed supplemented cows than the control (18.6±0.8 vs 15.8±0.9 h; P<0.04). ...
... The mean diameter of largest POF did not differ signifi cantly (P=0.46) in both the groups ( Table 2). The fi nding is in concurrence with the earlier reports in dairy cattle (Petit et al., 2002;Robinson et al., 2002;Ponter et al., 2006;Zachut et al., 2011). In contrast, the greater diameter of the ovulatory follicle was observed in dairy cows fed diets rich in n-3 PUFA (Ambrose et al., 2006;Bilby et al., 2006). ...
Article
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The objective of the present study was to examine the effect of dietary n-3 PUFA supplementation on oestrus response in the goat following synchronization with prostaglandin analogue. Parous cycling goats (n=17/group) were fed a concentrate diet supplemented with either fi sh oil (FO) or palm oil (PO). The FO provided n-3 EPA and DHA @ 156 mg kg-1 body weight while PO was given @ 0.6 ml kg-1 body weight to make the diet isocaloric. Oestrus was synchronized using two dose of prostaglandin F 2α (PGF 2α) at 11 days apart, with fi rst PG on day 25 of oil supplementation. Goats were observed for oestrus twice a day using a vasectomized teaser buck following second injection of PGF 2α. The number and diameter of preovulatory follicle (POF) on the day of oestrus was studied using transrectal ultrasonography. The mean interval from PGF 2α administration to the onset of oestrus was signifi cantly (χ 2 df1 =7.003, P=0.008) longer in FO than PO supplemented goats (48.71±3.78 vs 37.41±1.75 h). The proportion of goats showed oestrus within 48 h was 94.11% in the PO group (16/17), while it was 58.82% in the FO group (10/17). However, the oestrus duration was not affected by the FO supplementation. The number of POF was higher in the FO group than the PO (2.23±0.14 vs. 1.82±0.15; P=0.054); however the diameter of POF did not differ among the group (6.90±0.10 vs. 6.77±0.14; P>0.05). In conclusion, the supplementation of goats with n-3 PUFA rich FO delayed the onset of PGF 2α induced oestrus and increased the POF number on the day of oestrus.
... Similarly, Guardieiro et al. (2014) did not find changes in embryo production after the superstimulation of non-bred and non-lactating Nellore heifers supplemented with rumen-protected fat rich in LA. Thus, the published results concerning specific lipids used as nutritional supplementation for cattle are contradictory because most of the time it is difficult to know whether the effect of diet on oocyte and embryo quality (Cerri et al. 2009;Leroy et al. 2010) is due to the direct effects of certain fatty acids, altered metabolite concentrations in the follicular fluid microenvironment (Zachut et al. 2011) or variations in the plasma concentrations of metabolites and hormones (Leroy et al. 2010;Zachut et al. 2011). Moreover, most studies in the literature were performed in dairy cattle and, because of differences in dry matter intake and the level of milk production, these studies are not directly applicable to beef cattle (Funston 2004). ...
... Similarly, Guardieiro et al. (2014) did not find changes in embryo production after the superstimulation of non-bred and non-lactating Nellore heifers supplemented with rumen-protected fat rich in LA. Thus, the published results concerning specific lipids used as nutritional supplementation for cattle are contradictory because most of the time it is difficult to know whether the effect of diet on oocyte and embryo quality (Cerri et al. 2009;Leroy et al. 2010) is due to the direct effects of certain fatty acids, altered metabolite concentrations in the follicular fluid microenvironment (Zachut et al. 2011) or variations in the plasma concentrations of metabolites and hormones (Leroy et al. 2010;Zachut et al. 2011). Moreover, most studies in the literature were performed in dairy cattle and, because of differences in dry matter intake and the level of milk production, these studies are not directly applicable to beef cattle (Funston 2004). ...
Article
Dietary rumen-protected polyunsaturated fatty acids (PUFAs) rich in linoleic acid (LA) may affect embryo yield, and LA can modulate the molecular mechanisms of lipid uptake in bovine blastocysts produced in vitro. In embryos, membrane lipids, such as phosphatidylcholines (PCs) and sphingomyelins (SMs), affect cryopreservation success. The aim of the present study was to evaluate embryonic developmental rates after the IVF of oocytes retrieved from Nellore heifers fed for approximately 90 days with rumen-protected PUFAs rich in LA. In addition, we evaluated embryo cryotolerance and the membrane structure lipid composition using matrix-assisted laser desorption ionisation mass spectrometry of fresh and vitrified embryos. Embryo development to the blastocyst stage (mean 43.2%) and embryo survival after vitrification and warming (mean 79.3%) were unaffected by diet. The relative abundance of one lipid species (PC ether (PCe; 38:2, which means that this lipid has 38 carbon atoms and 2 double bonds in the fatty acyl residues) was increased after PUFAs supplementation. However, 10 ions were affected by cryopreservation; ions consistent with PC 32:0, PC 34:1, SM 24:1, PC 40:6 or PC 42:9, PC plasmalogen (PCp) 44:10 or PC 42:7, triacylglycerol (TAG) 54:9 and a not assigned ion (m/z 833.2) were lower in blastocysts that survived to the cryopreservation process compared with fresh blastocysts, whereas the abundance of the ions PC 36:3 or PC 34:0, PCe 38:2 or PC 36:6 and PC 36:5 or PCe 38:1 were increased after cryopreservation. Thus, the results demonstrate that the mass spectrometry profiles of PC, SM and TAG species differ significantly in bovine blastocysts upon cryopreservation. Because the lipid ion abundances of fresh and vitrified-warmed embryos were distinct, they can be used as potential markers of post-cryopreservation embryonic survival.
... One difficulty with interpretation is that the PG assays used (which are mainly antibody-binding assays) generally fail to differentiate 2-series from 3-series PGs as this can only be done reliably following separation by high performance liquid chromatography or gas/liquid chromatographymass spectrometry systems. Feeding dairy cows with a high n-3 PUFA diet resulted in a lower level of PGE in the follicular fluid from large follicles [73]. Similarly feeding fish oil to mice deceased ovarian production of both PGF2 and PGE via reduced PTGS2 [70]. ...
... Similarly, Zachut et al. [96] found that dairy cows fed a high n-3 PUFA diet exhibited longer intervals from being given a PGF 2a injection to manifestation of oestrus behaviour, which delayed the beginning of the subsequent luteal phase. This group of animals also showed a longer duration of their pre-ovulatory oestradiol surge [73]. ...
... Lammoglia et al. (1996) In the current study, there was no significant difference observed in the onset of estrus within treatments in cows managed either on pasture or in confinement. Zachut et al. (2011) reported that the onset of estrus after the PGF 2 injection was numerically delayed in E-flax (extruded flaxseed) fed cows compared to control. The onset of estrus after the 3 rd PGF 2 injection averaged at 1.8 ± 0.2 d in this study compared to 2.5 ± 0.3 d in other studies (Zachut et al. 2011 Zachut et al. 2010). ...
... Zachut et al. (2011) reported that the onset of estrus after the PGF 2 injection was numerically delayed in E-flax (extruded flaxseed) fed cows compared to control. The onset of estrus after the 3 rd PGF 2 injection averaged at 1.8 ± 0.2 d in this study compared to 2.5 ± 0.3 d in other studies (Zachut et al. 2011 Zachut et al. 2010). ...
... ALA can be converted into the eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3), the long chain n-3 PUFA. Supplementing EL and encapsulated flaxseed to dairy cows modified FA profiles of both the plasma and the ovarian compartments (i.e., follicular fluid, granulosa cells, cumulus-oocyte complexes) [12,13]. An increase in ALA and n-3 FA contents and a decrease in n-6:n-3 ratio were observed. ...
... g/cow/d compared to 1181 (±742.5) g/cow/d in 29 treatment diets from 21 trials studying EL and production performance [24], and to 826 g/cow/d, 1700 g/cow/d and 1745 g/cow/d in three trials studying EL and reproductive performance [13,19,21]. Thus, we lack the knowledge to comment on the largest magnitude of the association between DAI1 or DIAF and EL exposure with the lowest intake of EL (<50 g of EL, <11 g of ALA). ...
Article
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Feeding n-3 fatty acids (FA) is often cited as a promising strategy to tackle impaired reproduction in dairy cows. However, the scientific literature shows conflicting results that may be explained by the nature of n-3 FA used, the amount supplemented and the timing of supplementation. In addition, designing a proper experimental design to study n-3 FA and reproduction is subjected to other difficulties such as the choice of the control diet or gaining enough statistical power. The objective of this retrospective observational study was to quantify the average effects of supplementing extruded linseed (EL), a feed rich in α-linolenic acid, to dairy cows on reproductive performances under field conditions in French commercial farms. Exposure measurement to EL feeding was particularly challenging as exact cow diets are not traced in farms. Therefore, to investigate the potential dose-effect relationship, we defined a proxy of EL intake per day by using deliveries of EL based feeds from 22 companies in the study period 2008–2015 in France. An artificial insemination (AI) was considered exposed only if the cow was supplemented with EL from the calving until 17 days after AI. Based on recommendations for EL use on the field, 4 exposures classes were created: [1–50] (n = 14,126 AIs), [50–300] (n = 88,261 AIs), [300–600] (n = 66,136 AIs), and [600-1500] (n = 28,287 AIs) g/cow/d. The reference population was composed of cows that did not receive any EL between calving until 17 days after AI within herds that were supplied, but not continuously during the study period (n = 226,795 AIs). Mean daily EL intake in exposed population was 337 g/cow/d (±239.4). Reproductive performance was studied on 423,605 AIs from 1096 herds and 158,125 cows using Cox models for days to first AI and days to conception, and logistic regression models for risk of return-to-service, adjusted for factors likely to influence the reproductive performance and for a herd random effect. Risk of return-to-service between 18 and 78 days after first and second AI did not differ between exposed and reference populations, Nevertheless, the effect on the days to first AI was higher with the lowest EL intake (HR: 1.14; 95% CI: 1.11, 1.17) than with higher EL intake levels (HR ranging from 1.06 to 1.07; 95% CI: 1.04, 1.09). Similarly, for the effect on the time from calving to conception from the lowest EL intake (HR: 1.19; 95% CI: 1.15, 1.23) compared to the higher EL intake levels (HR ranging from 1.08 to 1.11; 95% CI: 1.06, 1.14). This original large-scale epidemiological study provides new insights into the effects of feeding EL at a commercially sustainable level to dairy cows.
... In the current study, there was no significant difference observed in the onset of estrus within treatments in cows managed either on pasture or in confinement. Zachut et al. (2011) reported that the onset of estrus after the PGF reported that the diameter of the large follicle ( 10 mm) was greater in fish oil fed dairy cows compared to the control diet fed cows (17.1 mm vs. 14.3 mm). The differences in follicle diameter in these groups might be explained by differences in EPA and DHA content of lipid supplements. ...
Research
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The objectives of this study were to evaluate the effect of rumen-protected fish oil (RPFO) and rumen-protected marine algae (RPMA) supplements on ovarian function of lactating dairy cows on pasture or in confinement during the estrus and ovulation synchronization period. Thirty-six Holstein cows were assigned to one of the two feeding systems and fed with lipid supplements from 30d before to 100d after calving. The resumption of cyclicity and onset of estrus were not influenced by LS. Mean daily number of the large follicles was similar across the treatments. During the Ovsynch period, RPFO treated cows had larger follicles (10mm; P<0.05). Ovulation was delayed in RPFO and RPMA group but the number of ovulation was not altered. The number and diameter of CL were greater in the RPMA group. Progesterone concentrations were greater in the RPMA group on pasture (P<0.05). These findings indicate that RPMA supplementation improves the ovarian function.
... Nevertheless, when comparison in the present study was made between the serum and the follicular fluid FA profiles, no significant differences were revealed. The latter is in agreement with the literature (34) indicating that FAs profiles of the FF are very similar to those in the serum. Since follicular fluid obtains metabolites partly from the serum (14), any dietary alterations that are effectively transferred in the serum may modify the fatty-acid composition of the follicular fluid, which, in its turn can be crucial for altering ovarian activity and oocyte environment (17,35). ...
Article
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The objectives of the present study were to examine the fatty acid (FA) profiles in serum and in the follicular fluid (FF) and the association between polyunsaturated fatty acid level (PUFA) and follicular growth dynamics following induced luteolysis in dairy cows. A total of 29 dairy cows (CL>25mm, follicle≈15mm) at d0 (start of the experiment) were submitted to ultrasound guided transvaginal follicular aspiration for FF collection from the largest follicle and were injected with 500 μg of cloprostenol. The cows were subdivided into Group A1 (n=11) and Group A2 (n=8) resuming follicular growth either from a secondary follicle less than or larger than 8.5mm, respectively, present at the moment of aspiration and Group A0 (n=10) not resuming follicular growth. Follicular development was monitored daily by ultrasonography until the next dominant follicle reached ≈15mm and was subsequently punctured in Group A1 and A2 (d1). Serum and FF samples for FA determination were taken at d0 from all cows and at d1 in Group A1 and A2. No differences were observed between the FA profile in serum nor in FF between sampling days. Regarding the PUFA levels, the serum linoleic acid (C18:2n6) levels at d0 and d1 were significantly higher than in FF, while alpha linolenic acid (C18:3n3) was lower in the serum than in FF, both at d0 and d1. At d0, a tendency for negative correlation between serum and the FF C18:2n6 with subsequent daily follicular growth rate was observed, while, at d1 there was a strong negative correlation between the serum C18:2n6 and daily growth rate (r=-0.71; p=0.0006). The present study revealed similarities of the FA profiles in the serum and in the FF and association between serum and FF PUFA content with the follicular dynamics after induced luteolysis.
... In female mammals, diets enriched in n-3 PUFA enhance plasmatic levels of 17β-estradiol (E2) [232,247,248], thereby leading to increased secretion of GnRH and triggering the LH surge. The mechanism behind the enhanced E2 synthesis is still unclear; however, several explanations have been suggested: PUFA supplementation might enhance plasma steroid concentrations by increasing the availability of lipoprotein-cholesterol, by modulating PG synthesis, or by directly stimulating ovarian steroidogenesis [249,250]. ...
Article
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In female mammals, mechanisms have been developed, throughout evolution, to integrate environmental, nutritional and hormonal cues in order to guarantee reproduction in favorable energetic conditions and to inhibit it in case of food scarcity. This metabolic strategy could be an advantage in nutritionally poor environments, but nowadays is affecting women's health. The unlimited availability of nutrients, in association with reduced energy expenditure, leads to alterations in many metabolic pathways and to impairments in the finely tuned inter-relation between energy metabolism and reproduction, thereby affecting female fertility. Many energetic states could influence female reproductive health being under- and over-weight, obesity and strenuous physical activity are all conditions that alter the profiles of specific hormones, such as insulin and adipokines, thus impairing women fertility. Furthermore, specific classes of nutrients might affect female fertility by acting on particular signaling pathways. Dietary fatty acids, carbohydrates, proteins and food-associated components (such as endocrine disruptors) have per se physiological activities and their unbalanced intake, both in quantitative and qualitative terms, might impair metabolic homeostasis and fertility in premenopausal women. Even though we are far from identifying a "fertility diet", lifestyle and dietary interventions might represent a promising and invaluable strategy to manage infertility in premenopausal women.
... In contrast, switching to n-3 at 14 DIM, immediately increased 18:3n-3 concentration two-fold in BP, FF and MF for SHORT at the end of the supplementation period and over a three-fold for the 22:6n-3 in BP, FF and MF for LONG. Peripartal supplementation up to 92 g/kg DM of extruded flaxseed increased 5.3-fold in BP, 5.1- fold in MF ( ) and 8.1-fold in FF collected at 63 and 96 DIM (Zachut et al., 2011). Flaxseed, after various treatments ( Mustafa et al., 2003;Gonthier et al., 2005) provoked similar changes in BP as observed in our study. ...
... Or, omega-3 may be caused to raise cholesterol in the peripheral fluid and the fat is the main material for the formation of steroid hormones, including progesterone, on the other hand, it inhibits the manufacture of prostaglandins as the linoleic fatty acid greatly affects the enzyme (Cyclooxygenase COX-2) and then Preventing PGF2α formation, preventing yellow body degradation, perpetuating pregnancy, and high fertility in goats [19].The results in Table 4 indicate that there was no significant effects (P>0.05) of Omega-3 giving on the percentage of twins in the transactions under study, the rates are 35, 35 and 33%, which are consistent with what was mentioned by [20]. The results also showed a significant decrease (P≤0.01) on a silent estrus rate, on goats in the third group T3 which was given Omega-3 by 40 ml as silent estrus rate was 20% compared to the group T1 and T2 at a rate of 40% each, and the significant decrease in The missed rate of goats who gave 40 ml of omega-3 to the significant omega-3 effect on increasing the concentration of ovulation hormone LH and estrogen in ruminants [21]. Table 4 also shows that giving omega-3 at a rate of 40 ml has led to a significant improvement (P≤0.01) in the number of births per abdominal 1.20 and outperformed both groups T1 and T2 as it reached 0.70 and 1.0 respectively, and the increase in the number Born in one abdomen until giving omega-3 has improved the development of follicles through the metabolism of hormones and their effect on the secretion of GnRH from the hypothalamus, this in turn stimulates the secretion of FSH and LH hormones from the frontal lobe of the pituitary gland in addition to the positive effect of Omega-3 in increasing Preparation and size of large follicles and by outcome leads to improvement in the volume of births per abdomen in goats [22][23][24]. ...
... In mammalian spermatozoa, long-chain polyunsaturated fatty acids of the n-3 family, in particular docosahexaenoic acid (DHA; C22:6n-3), are predominant (Petit et al., 2007;Zachut et al., 2011). These fatty acids Argov-Argaman et al. (2013) that such alterations might affect the semen's capacity to successfully undergo the cryopreservation procedures, which are widely used in intensive reproduction management. ...
... Assim, supõe-se que esses ácidos são importantes para a produção dos oócitos e de embriões ( STURMEY et al., 2009). Animais suplementados com linhaça, rica em ácido linolênico (n-3), no período pré e pós-parto apresentaram retorno à ciclicidade, pico de LH e de estrógeno mais precocemente em relação aos animais que não receberam esse tipo de dieta ( ZACHUT et al., 2011). Isso explica as possíveis ligações entre os AGPs, metabólitos e início do estro. ...
... It has been reported that abomasal infusion of linseed oil showed insulin-sensitizing as well as antilipolytic effects in non-lactating cows (Pires et al., 2008). Also, feeding whole flaxseed to transition dairy cows resulted in a better performance, improved blood metabolic profile and liver function (Lessard et al., 2004;Zachut et al., 2011). However, enriching diets with omega-3-rich FA (n-3 FAs), such as by supplementing linseed, may concurrently predispose cows to experience more symptoms of oxidative stress and subsequently disturb metabolic homeostasis (Gobert et al., 2009). ...
... Selective uptake of fatty acids by the oocytes shows sensitivity to changes in the membrane composition. This may lead to changes in membrane properties, such as, for example, changes in the viscosity and membrane performance characteristics (12,26,27). ...
Article
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Feed fats are commonly used as a component of high-yielding cow diet rations. Many studies have been conducted on the effects of fat supplementation on metabolism, milk composition, and improvements in dairy cow reproduction. The positive effects on fat (vegetable oil) and energy supplementation on improvements in reproduction are well documented. Consumption of polyunsaturated fatty acids (PUFAs), including n-3 acids, in appropriate feed doses improves fertility of dairy cows. A fat source with high levels of acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is marine oil, especially fish and algae. By modification of cow rations, EPA and DHA can be utilized to reduce synthesis of PGF 2α in the endometrium, which can prevent luteolysis of the corpus luteum during early pregnancy. The PUFAs also may have a direct impact on key genes and their proteins that regulate biochemical processes and pathways between the corpus luteum, the uterus, and the embryo. The effect of n-3 fatty acids on the survival of embryos is not yet clearly defined.
... Therefore, the primary focus of our study was to describe FF FAs, rather than to investigate their relation to the serum composition. We furthermore did not have any knowledge on diet or fasting before sampling, even though it has been well described that diet can change the FF FA composition and can thereby affect oocyte developmental competence and subsequent embryo quality [48]. ...
Article
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It has been well documented that the maturing oocyte is very vulnerable to changes in its micro-environment, the follicular fluid (FF). Recent research has focused on different components within this FF, like hormones, growth factors and metabolites, and how their concentrations are altered by diet and the metabolic health of the mother. It has been proposed that fatty acids (FAs) are potential factors that influence oocyte maturation and subsequent embryo development. However, a thorough study of the specific FF FA composition per lipid fraction and how this may be affected by BMI is currently lacking. Therefore, we investigated the BMI-related concentration of FAs in the phospholipid (PL), cholesteryl-ester (CHE), triglyceride (TG) and non-esterified (NE) lipid fraction in the FF of women undergoing assisted reproductive treatment (ART). Methods: In this descriptive cross-sectional study, the FF of normal weight (18.5
... Similar responses were observed earlier with abomasal infusion of flax oil (Côrtes et al., 2011), with ALA in FFA form (Khas-Erdene et al., 2010) or with C18:1 cis-9 infusion (Drackley et al., 2007). In studies where flaxseed was fed rather than infused postruminally, milk fat percentage was decreased (Mustafa et al., 2003;Petit et al., 2007;Chilliard et al., 2009;Zachut et al., 2010Zachut et al., , 2011, but not in the others (Gonthier et al., 2005;Akraim et al., 2007). Milk fat responses to feeding flaxseed are most likely due to generation of unique FA isomers during rumen biohydrogenation of unsaturated FA (Bauman and Griinari, 2003). ...
Article
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The objectives of the present study were to evaluate the transfer efficiency of α-linolenic acid (ALA) from the abomasum into milk fat, its interaction with milk fat content and yield, and the relationship between ALA and C16:0 in milk fat. Three rumen-fistulated multiparous Holstein cows at midlactation were used in a 3×3 Latin square design. Treatments consisted of abomasal infusion of (1) 110 mL of water/d (control), (2) 110 mL of flaxseed oil/d (low flaxseed oil, LFO), and (3) 220 mL of flaxseed oil/d (high flaxseed oil, HFO). Experimental periods were continued for 2 wk and fat supplements were infused abomasally during the last 7 d of each period. Average dry matter intake and milk yield were not affected by oil infusion. Milk fat and lactose content tended to be greater with flaxseed infusion compared with the control. Plasma ALA was 2.9- and 4.0-fold greater with LFO and HFO, respectively. The apparent transfer efficiency of ALA to milk was 44.8 and 45.7% with LFO and HFO, respectively. The C16:0 content in milk fat was decreased by 3.59 and 5.25 percentage units, whereas the ALA content was increased by 1.68 and 3.09 percentage units with LFO and HFO, respectively. Similarly, C18:2n-6 was increased by 0.95 and 1.31 percentage units with LFA and HFO, respectively, without changes in other fatty acids (FA). Total polyunsaturated FA was 4.4 and 2.7% lower in the HFO and LFO, respectively, than in the control. Furthermore, C16:0 content in the milk fat was reduced to a greater extent than the increase in ALA content, as a 1.68 and 3.09 percentage unit increase occurred in ALA compared with a 3.6 and 5.25 percentage unit decrease in C16:0 for LFO and HFO, respectively, such that a negative correlation existed between ALA and C16:0 (r=-0.72). In conclusion, abomasal infusion of flaxseed oil dramatically increased the ALA content in plasma and milk fat. Because the replacement of C16:0 with ALA and C18:2n-6 occurred without changes in other FA presumed to be synthesized de novo in the mammary gland, this suggests that the preformed C16:0 was replaced, rather than being caused, by an overall suppression of de novo FA synthesis in the mammary gland.
... The incorporation of dietary long-chain FAs into plasma in ruminants was examined in several studies [18][19][20]. In a study in milking cows, the proportion of ALA in plasma increased from 1.03% in the control cows to 5.43% in cows, i.e., a 5.27-fold increase [19]. ...
... Similarly, a longer interval of behavioral estrus after PGF 2a injection was reported in the dairy cow supplemented with n-3 PUFA rich flaxseed [28]. Further, Zachut et al. [29] also observed that linseed diet increased the PGF 2a induced estrus by 3.6 h in the cow. It can be suggested that FO altered the dynamics of PGF 2a induced CL regression. ...
Article
Dietary supplementation of n-3 PUFA decreases the luteolytic PGF2α and improves the pregnancy rate in the dairy cow. However, its effect in the goat is not known. Accordingly, we studied the effect of supplementation of n-3 PUFA rich Fish oil (FO) on different reproductive events in the goat. Cycling goats (n = 30) were divided into two equal groups and fed an isocaloric and isonitrogenous diet supplemented with either FO (TRT; n = 15) or palm oil (PO) (CON; n = 15) @ 0.6 mL/kg body weight for 72 days. Estrus synchronization was done on day 25 and 36 of supplementation using two PG regimen and the goats in estrus were bred. Mean interval from PGF2α administration to the onset of estrus was 12 h longer (P < 0.05) in the TRT group than that of CON. The number of preovulatory follicles (POF) and ovulation rate was significantly higher in FO supplemented goats (P < 0.05) by 39.64 and 41.35%, respectively. Though the Corpus luteum diameter was significantly higher (P < 0.05) on day 5, 8 and 11 post breeding in the TRT group, mean serum progesterone (P4) did not differ significantly (P > 0.05). Mean concentration of serum estradiol (E2) was significantly (P < 0.01) lower in the FO supplemented group during day 0–60 post-breeding which could be due to significantly low serum cholesterol (P < 0.01). Though the serum concentration of PGF2α metabolite (PGFM) and PGE2 metabolite (PGEM) in the pregnant goats was significantly (P < 0.05) lower in the TRT group on day 16 and 17 post-breeding, the ratio of PGEM to PGFM remained unaffected suggesting a favourable effect of FO supplementation on the early pregnancy. The number of embryos, twinning rate and kidding rate were high in FO supplemented group though it was non-significant. However, gestation length, birth weight of kids and neonatal behaviour were comparable between the groups (P > 0.05). In conclusion, supplementation of n-3 PUFA rich FO significantly increased the number of POF and ovulation rate with numerical increase in the kidding rate. Further, it decreased the serum E2 and PGFM during the critical window of pregnancy recognition in the doe.
... Further, no difference in the duration of estrus onset between FO and PO groups could be due to the lack of functional CL in the seasonally acyclic goats. Alpha-linolenic rich linseed diet increased the PGF 2α induced estrus by 3.6 h with longer plasma LH and E 2 peak in the cow (Zachut et al. 2011). Overall, the results indicate that the estrus onset and its duration were within the physiological limits in most studies. ...
Article
We have shown that dietary supplementation of n‐3 polyunsaturated fatty acid (n‐3 PUFA) rich fish oil (FO) around the breeding time improved the utero‐ovarian functions in the goat.Here, we investigated the effect of FO supplementation during the periparturient period on serum n‐3 PUFA, prostaglandin F2α metabolite (PGFM), placental expulsion, uterine involution, resumption of estrus and neonatal vigour.Rohilkhandi goat in advanced gestation (n=16) were divided into two equal groups. Onegroup wassupplemented with FO containing 26% n‐3 long chain PUFA at the rate of 156 mg per kgbody weight,while the control group wasfed isocaloric palm oil (PO) from ‐3 to +3 week of kidding.Dietary FO increased serum concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by 7.3and 6.6 fold, respectively after 6 weeks of supplementation. Goats in FO groupexpelled the fetal membranes 99.1 min earlier (P<0.01) than those of PO group. Further, dietary FO significantly decreased the serum PGFM on day 7 postpartum. However, no difference was found on uterine involution, which was completeby day 20 postpartum in either group. Resumption of follicular activity by day 5 postpartum was 87.5% in the FO as compared to 25% in the PO group (P<0.05). Similarly, occurrence of behavioral estrus by day 90 postpartum was 57.1% in goats of the FO group while none of does wasin the PO group (P<0.01) expressed estrus. It was concluded that feeding FO rich diet during ‐3 to +3 weeks of kidding decreased the PGFM till day 7 postpartum, hastened the expulsion of fetal membranes and reduced the time from kidding to first postpartum estrus in Rohilkhandi does.
... The results in Table 4 indicate that there was no significant effects (P>0.05) of Omega-3 giving on the percentage of twins in the transactions under study, the rates are 35, 35 and 33%, which are consistent with what was mentioned by Childs and his colleagues, 2008. The results also showed a significant decrease (P≤0.01) on a silent estrus rate, on goats in the third group T3 which was given Omega-3 by 40 ml as silent estrus rate was 20% compared to the group T1 and T2 at a rate of 40% each, and the significant decrease in The missed rate of goats who gave 40 ml of omega-3 to the significant omega-3 effect on increasing the concentration of ovulation hormone LH and estrogen in ruminants (Zachut et al. 2011). Table 4 also shows that giving omega-3 at a rate of 40 ml has led to a significant improvement (P≤0.01) in the number of births per abdominal 1.20 and outperformed both groups T1 and T2 as it reached 0.70 and 1.0 respectively, and the increase in the number Born in one abdomen until giving omega-3 has improved the development of follicles through the metabolism of hormones and their effect on the secretion of GnRH from the hypothalamus, this in turn stimulates the secretion of FSH and LH hormones from the frontal lobe of the pituitary gland in addition to the positive effect of Omega-3 in increasing Preparation and size of large follicles and by outcome leads to improvement in the volume of births per abdomen in goats (Moallem et al., 1999and Mossa et al., 2007and De Veth et al., 2009). ...
Article
Full-text available
This experiment included 27 Cypriot goats with a weight of 34-48 kg. They were randomly distributed into three groups of equal number (Nine goat in each group). The first group (T1) control group (T2) the second group was given 20 ml / Omega-3 per animal and the third group (T3) was given 40 ml / Omega-3 per animal. The results showed that there was a proper effect of treatment with omega-3 on milk production of Cypriot goats during October, November and December. The third treatment was properly superior (P≤0.05) at a rate of 1.62 ± 52.30, 1.76 ± 36.00 and 2.00 ± 33.71 kg for the first treatment (Control), which that recorded during the same months 1.80 ± 28.00, 1.10 ± 19.44 and 1.68 ± 18.90 kg, respectively. The results of the current study also indicate a significant increased (P ≤0.05) for the third treatment was given 40 ml omega-3 in the fertility rate of Cypriot goats that reached 80% compared to the control group whose fertility rate reached 60%, the results showed that the percentage of fertility increased significantly (P≤0.05) for goats in the third group to 90%, while the group T2 and T1 scored 70%, also the percentage of births improved significantly (P≤0.01) among the goats in the third group that were given 40 ml of omega-3 by a rate of 90 % Compared to the group T1 and T2 as it reached 60%. The results showed no significant effect of omega-3 on the percentage of twins, as it reached group T1 and T2 as it reached 35% compared to group T3 33%. The results indicated a significant decrease on a silent estrus percentage for goats in the third group T3 when given 40 ml of omega-3 to 20% compared to the group T2 and T1 at a rate of 40%. The results also showed a significant improvement in the number of births per abdomen among goats of the third group, which gave 40 ml of omega-3 as the rate was 1.20 compared to the groups T1 and T2 as they reached 0.70 and 1.0, respectively. The omega-3 administration of goats was not reported to have any significant effect on the pregnancy duration of three groups, it appears through the results of the study, that is giving omega-3 has significantly increased dramatically the reproductive performance and a lesser degree the productive performance of Cypriot goats in Iraq.
... Feeding of unsaturated fatty acids (UFAs) is shown to improve the ovarian follicle biochemical profile, improve progesterone (P4) during the luteal cycle, and modulate prostaglandins during early pregnancy [5,91,92]. Polyunsaturated fatty acids (PUFAs), such as fish oil-based rumen protected supplementation, are the best in the class of dietary fats, which are shown to improve ovarian follicle growth, increase insemination success, and are helpful in the prevention of pregnancy losses [93,94]. Peroxisome proliferator activated receptors (PPARs) have an integral role in embryonic development and early pregnancy through lipid metabolism support. ...
Article
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Early successful conception of postpartum dairy cows is crucial in determining the optimum reproductive efficiency and profitability in modern dairy farming. Due to the inherent high production potential of modern dairy cows, the extra stress burden of peri-parturient events, and associated endocrine and metabolic changes causes negative energy balance (NEBAL) in postpartum cows. The occurrence of NEBAL is associated with excessive fat mobilization in the form of non-esterified fatty acids (NEFAs). The phenomenon of NEFA mobilization furthers with occurrence of ketosis and fatty liver in postpartum dairy cows. High NEFAs and ketones are negatively associated with health and reproductive processes. An additional burden of hypocalcemia, ruminal acidosis, and high protein metabolism in postpartum cows presents further consequences for health and reproductive performance of postpartum dairy cows. This review intends to comprehend these major nutritional metabolic alterations, their mechanisms of influence on the reproduction process, and relevant mitigation strategies.
... Similarly, when cows are supplemented with 10 g of C20:5n-3, their rate of pregnancy and pregnancy per artificial insemination are increased [357]. Enrichment of n-3 PUFA in membrane of ovarian compartment can also affect prostaglandins synthesis in cows as demonstrated by supplementation of dairy cows with extruded linseed [358]. ...
Article
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High producing dairy cows generally receive in the diet up to 5–6% of fat. This is a relatively low amount of fat in the diet compared to diets in monogastrics; however, dietary fat is important for dairy cows as demonstrated by the benefits of supplementing cows with various fatty acids (FA). Several FA are highly bioactive, especially by affecting the transcriptome; thus, they have nutrigenomic effects. In the present review, we provide an up-to-date understanding of the utilization of FA by dairy cows including the main processes affecting FA in the rumen, molecular aspects of the absorption of FA by the gut, synthesis, secretion, and utilization of chylomicrons; uptake and metabolism of FA by peripheral tissues, with a main emphasis on the liver, and main transcription factors regulated by FA. Most of the advances in FA utilization by rumen microorganisms and intestinal absorption of FA in dairy cows were made before the end of the last century with little information generated afterwards. However, large advances on the molecular aspects of intestinal absorption and cellular uptake of FA were made on monogastric species in the last 20 years. We provide a model of FA utilization in dairy cows by using information generated in monogastrics and enriching it with data produced in dairy cows. We also reviewed the latest studies on the effects of dietary FA on milk yield, milk fatty acid composition, reproduction, and health in dairy cows. The reviewed data revealed a complex picture with the FA being active in each step of the way, starting from influencing rumen microbiota, regulating intestinal absorption, and affecting cellular uptake and utilization by peripheral tissues, making prediction on in vivo nutrigenomic effects of FA challenging.
... An indirect approach to investigate the proposed impact of a NEB status on oocyte growth and hence quality during the early stages of follicular development may be via manipulations during the transition period of the cow, for example by means of diets that are highly enriched with 'encapsulated fatty acids', fatty acids packed in for example calcium salts to overcome the biohydrogenation from unsaturated to saturated fatty acids in the rumen of the cow (Jenkins and Palmquist, 1984;Nafikov and Beitz, 2007). It has been shown that fatty acids from the diet are reflected in the total fatty acid fraction, including the fatty acids present in lipoproteins, of blood and follicular fluid (Wonnacott et al., 2010;Zachut et al., 2011). Many studies have focused on the effects of feeding commercially available conjugated poly-unsaturated fatty acids, like linoleic (C18:2) and linolenic acid (C18:3), with different aims including the improvement of fertility, with variable outcomes (Santos et al., 2008;Leroy et al., 2014;Rodney et al., 2015Rodney et al., , 2018. ...
Article
Metabolic stress in humans and animals is associated with impaired fertility. A major characteristic of metabolic stress is elevated levels of free fatty acids (NEFAs) in blood due to mobilization of body fat reserves. Dairy cows undergo a period of metabolic stress during the peri-calving period, the so-called negative energy balance (NEB) in the early weeks postpartum. At the time of NEB, both saturated and unsaturated NEFAs are mobilized to serve as an alternative energy supply for cells, however in particular saturated NEFAs can have a detrimental effect on somatic cells. Circulating NEFAs are also reflected in the follicular fluid of ovarian follicles and hence reach the cumulus-oocyte-complex (COC), which implies a potential risk for the developing oocyte. To this end, the current review focusses on the impact of NEFAs on the quality of the oocyte.
... Further, no difference in the duration of estrus onset between FO and PO groups could be due to the lack of functional CL in the seasonally acyclic goats. Alpha-linolenic rich linseed diet increased the PGF 2α induced estrus by 3.6 h with longer plasma LH and E 2 peak in the cow (Zachut et al. 2011). Overall, the results indicate that the estrus onset and its duration were within the physiological limits in most studies. ...
Article
Full-text available
We have shown that dietary supplementation of n‐3 polyunsaturated fatty acid (n‐3 PUFA)‐rich fish oil (FO) around the breeding time improved the utero‐ovarian func‐ tions in the goat. Here, we investigated the effect of FO supplementation during the periparturient period on serum n‐3 PUFA, prostaglandin F2α metabolite (PGFM), placental expulsion, uterine involution, resumption of oestrus and neonatal vigour. Rohilkhandi goat in advanced gestation (n = 16) was divided into two equal groups. One group was supplemented with FO containing 26% n‐3 long‐chain PUFA at the rate of 156 mg per kg body weight, while the control group was fed isocaloric palm oil (PO) from −3 to +3 week of kidding. Dietary FO increased serum concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by 7.3‐ and 6.6‐fold, respectively, after 6 weeks of supplementation. Goats in FO group expelled the foe‐ tal membranes 99.1 min earlier (p < .01) than those of PO group. Further, dietary FO significantly decreased the serum PGFM on day 7 post‐partum. However, no differ‐ ence was found on uterine involution, which was complete by day 20 post‐partum in either group. Resumption of follicular activity by day 5 post‐partum was 87.5% in the FO as compared to 25% in the PO group (p < .05). Similarly, occurrence of be‐ havioural oestrus by day 90 post‐partum was 57.1% in goats of the FO group while none of does was in the PO group (p < .01) expressed oestrus. It was concluded that feeding FO‐rich diet during −3 to +3 weeks of kidding decreased the PGFM till day 7 post‐partum, hastened the expulsion of foetal membranes and reduced the time from kidding to first post‐partum oestrus in Rohilkhandi does.
... Recently, there has been a great deal of interest in feeding fat to dairy cows in order to increase energy density of the diet and improve reproduction (Oldick et al.1997 and Staples the potential to have the opposite effect. The times to behavioural oestrus and plasma LH and E2 peak were numerically longer when cows were supplemented with a high omega-3 linseed diet pre-and post-partum (Zachut et al., 2011). Keeping in view the above-mentioned facts, the present research work was undertaken on dietary supplementation of soybean oil and crushed linseed in postpartum cows for improving the reproductive performance in terms of estrus attributes. ...
Article
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The study was undertaken to find out the effect of dietary supplementation of crushed flaxseed and soyabean oil on estrus attributes in postpartum cows. Total 48 postpartum crossbred multiparous cycling cows with normal calving history were considered and divided into three groups viz., 15% crushed flaxseed (T 1), 3% soyabean oil (T 2) and Control (T 3-no additional fat). Cows from all the groups were subjected to an ovsynch synchronization protocol on day 60 postpartum treated with Inj. Buserelin acetate 10µg i/m on day 0, Inj. Cloprostenol sodium 500 µg on day 7 and Inj. Buserelin acetate 10µg i/m on day 9, to observe induced estrus response, time required for onset of induced estrus, intensity and duration of induced estrus respectively. The induced oestrus response was numerically highest in group fed with Soyabean oil. It was observed that the cows from soyabean oil followed by crushed flaxseed supplemented groups were numerically responded earlier to the PGF 2 α injection as compared to the cows from control group. The percent intense intensity of estrus was numerically higher in cows supplemented with soyabean oil followed by crushed flaxseed supplemented group as compared with control group. There was no significant difference between the groups for time required for onset of induced estrus and duration of oestrus, whereas it was observed that soybean oil fed cows responded earlier.
... A lower proportion of arachidonic acid was found in adipose tissues of cows fed a lower n -6: n -3 ratio (0.16% in controls vs. 0.06% in the n-3-supplemented cows; Zachut et al., 2010). Furthermore, in cows fed a diet with a lower n -6: n -3 ratio, we found a reduction in the proportion of arachidonic acid in follicular fluid of preovulatory follicles (2.08% in controls vs. 0.93% in the n-3 cows) and in granulosa cells (0.21% in controls vs. 0.03% in the n-3 cows; Zachut et al., 2011). Thus, the effects of n-3 fatty acids on the reproductive system might be partly mediated by the reduced availability of arachidonic acid. ...
... The results in Table 4 indicate that there was no significant effects (P>0.05) of Omega-3 giving on the percentage of twins in the transactions under study, the rates are 35, 35 and 33%, which are consistent with what was mentioned by Childs and his colleagues, 2008. The results also showed a significant decrease (P≤0.01) on a silent estrus rate, on goats in the third group T3 which was given Omega-3 by 40 ml as silent estrus rate was 20% compared to the group T1 and T2 at a rate of 40% each, and the significant decrease in The missed rate of goats who gave 40 ml of omega-3 to the significant omega-3 effect on increasing the concentration of ovulation hormone LH and estrogen in ruminants (Zachut et al. 2011). Table 4 also shows that giving omega-3 at a rate of 40 ml has led to a significant improvement (P≤0.01) in the number of births per abdominal 1.20 and outperformed both groups T1 and T2 as it reached 0.70 and 1.0 respectively, and the increase in the number Born in one abdomen until giving omega-3 has improved the development of follicles through the metabolism of hormones and their effect on the secretion of GnRH from the hypothalamus, this in turn stimulates the secretion of FSH and LH hormones from the frontal lobe of the pituitary gland in addition to the positive effect of Omega-3 in increasing Preparation and size of large follicles and by outcome leads to improvement in the volume of births per abdomen in goats (Moallem et al., 1999and Mossa et al., 2007and De Veth et al., 2009). ...
Article
Full-text available
This experiment included 27 Cypriot goats with a weight of 34-48 kg. They were randomly distributed into three groups of equal number (Nine goat in each group). The first group (T1) control group (T2) the second group was given 20 ml / Omega-3 per animal and the third group (T3) was given 40 ml / Omega-3 per animal. The results showed that there was a proper effect of treatment with omega-3 on milk production of Cypriot goats during October, November and December. The third treatment was properly superior (P≤0.05) at a rate of 1.62 ± 52.30, 1.76 ± 36.00 and 2.00 ± 33.71 kg for the first treatment (Control), which that recorded during the same months 1.80 ± 28.00, 1.10 ± 19.44 and 1.68 ± 18.90 kg, respectively. The results of the current study also indicate a significant increased (P ≤0.05) for the third treatment was given 40 ml omega-3 in the fertility rate of Cypriot goats that reached 80% compared to the control group whose fertility rate reached 60%, the results showed that the percentage of fertility increased significantly (P≤0.05) for goats in the third group to 90%, while the group T2 and T1 scored 70%, also the percentage of births improved significantly (P≤0.01) among the goats in the third group that were given 40 ml of omega-3 by a rate of 90 % Compared to the group T1 and T2 as it reached 60%. The results showed no significant effect of omega-3 on the percentage of twins, as it reached group T1 and T2 as it reached 35% compared to group T3 33%. The results indicated a significant decrease on a silent estrus percentage for goats in the third group T3 when given 40 ml of omega-3 to 20% compared to the group T2 and T1 at a rate of 40%. The results also showed a significant improvement in the number of births per abdomen among goats of the third group, which gave 40 ml of omega-3 as the rate was 1.20 compared to the groups T1 and T2 as they reached 0.70 and 1.0, respectively. The omega-3 administration of goats was not reported to have any significant effect on the pregnancy duration of three groups, it appears through the results of the study, that is giving omega-3 has significantly increased dramatically the reproductive performance and a lesser degree the productive performance of Cypriot goats in Iraq.
Conference Paper
Abstract Objective – To investigate drug resistant patterns among Salmonella isolated from 2 different sources i.e. human and water samples. Materials and Methods – Agar well diffusion and broth macrodilution methods were employed for determining the drug resistant pattern and the MIC of 9 and 2 antimicrobials, respectively. Result- Susceptibility testing noted that at least 4 antimicrobials i.e. gentamycin, tetracycline, ofloxacin and kanamycin were potentially effective against the 32 Salmonella isolates from human and water sources. Conclusion – More antibiotic resistance was found among human isolates compared to isolates from water samples at broiler farm.
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We examined the effects of dietary n-3 fatty acids on the proteome of peripheral blood mononuclear cells (PBMC) in transition dairy cows. Forty-two dry cows were divided into three groups supplemented with: saturated fat (CTL); flaxseed oil (FLX); or fish oil (FO). PBMC were collected from five cows per group at week 1 postpartum for proteomic analysis. The n-3 fatty acid content in plasma and PBMC was higher in FLX and FO than in CTL cows. In PBMC, 3807 proteins were quantified and 44, 42 and 65 were differently abundant in FLX vs. CTL, FO vs. CTL and FLX vs. FO, respectively. In FLX vs. CTL, the abundance of the p65-subunit-of-transcription-factor NF-κB was higher, whereas albumin, C4b-binding protein and complement factor H levels were lower. In FLX vs. FO, complement factors B and H and hemopexin were higher. The top canonical pathway enriched in FLX compared to other groups was acute-phase-response signaling. The percentage of CD25+ blood cells was lower in FLX and FO at 1 week postpartum, and gene expression of NF-κB in white blood cells was lower in FLX than in CTL. Dietary sources of n-3 fatty acids differentially affected the proteome of PBMC, possibly altering the inflammatory status. Significance The transition dairy cow experiences a variable degree of systemic subacute inflammation, and proteomics of peripheral blood mononuclear cells (PBMC) may contribute to obtain insight into this process. Omega-3 fatty acids can moderate the immunological effect, and therefore we examined the effects of these fatty acids from flaxseed (FLX) or fish oils (FO) on the proteome of PBMC at week 1 postpartum. More than 3800 proteins were quantified, and in cows supplemented with FLX, enrichment of the acute-phase-signaling and complement systems were apparent in the PBMC compared to CTL and FO PBMC. This information may be useful to further explore the mechanism by which dietary omega-3 fatty acids affect the immune system in postpartum dairy cows.
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Beef demand has progressively decreased due to an increasing number of consumers who perceive beef as harmful to their health, among other causes. In contrast, functional foods are one of the fastest-growing markets. This study aims to analyse consumer preferences and estimates the willingness to pay for beef enriched with omega-3 fatty acids. We intend to identify and profile the potential market segments for functional beef and determine how the provision of information can affect consumer preferences. Data have been collected by applying a choice experiment on a sample of 757 Italian beef purchasers. The sample was randomly split into two information treatments plus a control group. Participants in the information treatments were given an explanation about the functional meat production system. Results showed that the average consumer has a preference for ω-3 enrichment and that information about the food's production process increases this preference. Therefore, the study reveals the existence of a potentially profitable market for functional beef.
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Among the long-chain fatty acids (FA), the omega-3 (n-3) FA have the most potent immunomodulatory activities. In the present large-scale study, we tested the effects of supplementation of α-linolenic acid (ALA) from flaxseed commenced at the dry period on milk yield, health and fertility of dairy cows. Cows in a large commercial dairy farm were randomly divided into two groups 21 days before expected calving. During the dry period, cows in the treatment group were fed a diet that contained, on a DM basis, 40 g/kg of an extruded flaxseed supplement (EFLX; n = 276); their postpartum diet contained 50 g/kg of the same supplement. The cows were group-fed, and based on average cow's intake, the EFLX cows consumed 80 and 220 g ALA/day per cow prepartum and postpartum, respectively. The control cows received a diet with a different composition but a similar content of nutrients (CTL; n = 240). A veterinarian routinely examined the cows 7 to 10 days after calving, treated them according to the farm's routine practice, and determined their body condition score at that visit and at peak lactation. Milk yield was 4.5% greater (1.8 kg/day; P < 0.0001), and fat (P < 0.0001) and protein (P = 0.002) contents were lower in the EFLX vs. CTL group. The proportion of n-3 FA in milk was 3.9 times higher in EFLX than in CTL cows (P < 0.0001), and the omega-6 (n-6):n-3 ratio in the milk fat decreased from 13.0 in the CTL cows to 4.1 in the EFLX cows (P < 0.0001). The unsaturated FA content in milk fat was 20.1% greater in EFLX than in CTL cows (P < 0.0001). Ketosis incidence was lower in the EFLX vs. CTL group, 23.5 and 31.2%, respectively (P = 0.05), and ketosis was less severe in the former (P = 0.03). The mortality rates in EFLX and CTL cows were 0.7 and 4.6%, respectively (P = 0.005). No differences were observed in conception rates at first or second insemination, but days from first service to conception and calving to conception were 17 (P = 0.07) and 18 days (P = 0.09) less in the EFLX cows, respectively. In conclusion, supplementation of EFLX to dairy cows from the dry period increased milk yield, decreased incidence of ketosis and severe metritis, reduced mortality, and tended to enhance fertility performance. Overall, ALA supplementation improved milk quality and was beneficial to the cow's health and fertility.
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Flaxseed is a rich source of lignans that can be metabolized to the mammalian lignan enterolactone (EL), which may elicit weak estrogenic or antiestrogenic effects. The objectives of this study were to examine the effects of feeding an extruded flaxseed supplement to dairy cows on concentrations of EL in plasma and preovulatory follicles and the association with intrafollicular estradiol (E2). Twenty-four multiparous 256-d-pregnant Israeli Holstein cows were fed either a standard diet both pre- and postpartum (control; n = 12) or provided with an extruded flaxseed supplement (n = 12), at 7.9 and 9.2% of DM, pre- and postpartum, respectively. Follicular fluid (FF) aspirations were conducted at 84 ± 16 d in lactation as follows: 7 to 8 d following behavioral estrus, cows were injected with prostaglandin F2a and 48 h later follicles >7 mm were aspirated. Follicles were regarded as preovulatory when the E2-to-progesterone ratio was >1. Plasma EL concentrations were not different between treatment groups; however, concentrations of EL in FF of preovulatory follicles were 1.7 times higher in extruded flaxseed-supplemented cows than in control. Across-treatment analysis revealed a positive correlation between concentrations of EL in plasma and in FF. In addition, intrafollicular EL concentrations were positively correlated with E2 concentrations (r = 0.50), and with the intrafollicular E2-to-progesterone ratio. In conclusion, supplementing dairy cows with extruded flaxseed increased EL concentrations in preovulatory follicles. Intrafollicular EL was correlated with E2 concentrations; therefore, the possible effects of EL from flaxseed on follicular steroidogenesis should be considered.
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Nutrition, and particularly dietary energy intake, plays a fundamental role in reproductive function in cattle. There is some evidence that supplemental omega-3 dietary polyunsaturated fatty acids (n-3 PUFA) can exert positive effects on fertility. The objectives of this study were to evaluate the effect of dietary n-3 PUFA supplementation, post-insemination energy plane of nutrition and their interaction on embryo survival in cattle. Crossbred beef heifers (n = 185) were individually offered barley straw ad libitum and 6 kg DM of concentrate supplemented with either a rumen-protected source of saturated fatty acid (palmitic; control, CON) or a partially rumen-protected n-3 PUFA-enriched supplement (n-3 PUFA). Estrous was synchronised using two injections of PG administered at 11-d intervals and following artificial insemination (AI = Day 0) 179 heifers exhibiting oestrus were inseminated and assigned to one of two dietary treatments: (i) remain on their pre-insemination high dietary plane of nutrition (High) or (ii) restricted to 0.6 × estimated maintenance energy requirements (Low) in a 2 × 2 factorial design. The heifers were then maintained on their assigned diets until slaughter and embryo recovery on Day 16 (n = 92) or pregnancy diagnosis by ultrasound scanning at Day 30 post-AI (n = 87). Plasma concentrations of fatty acids, metabolites, insulin, progesterone (P4) and insulin-like growth factor 1 (IGF-1) were measured at appropriate intervals. Hepatic expression of mRNA for aldo-keto reductase (AKR1C), cytochrome P450 2C (CYP 2C) and cytochrome P450 3A (CYP 3A) was examined. The n-3 PUFA supplementation increased plasma n-3 PUFA concentration (P < 0.05) and reduced n-6: n-3 PUFA ratio (P < 0.05). Plasma IGF-1 was higher for n-3 PUFA relative to the CON (P < 0.05) and for High compared with Low plane of nutrition post-AI (P < 0.05) groups. A low plane of nutrition post-AI increased plasma concentrations of progesterone from Days 7–16 after insemination (P < 0.001) but reduced embryo length (P < 0.001). Supplementation with n-3 PUFA reduced and tended to reduce hepatic expression of CYP2C (P = 0.01) and CYP3A (P = 0.08), respectively. However, while dietary n-3 PUFA supplementation and an abrupt reduction in nutrient status following insemination elevated plasma concentrations of n-3 PUFA and mid and late phase P4, respectively, there was no effect of either PUFA supplementation or post-insemination plane of nutrition on embryo survival.
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Flaxseed is useful as a functional food and alternative medicine owing to its beneficial health effects. Its action on ovarian cell functions and interrelationships with the upstream hormonal regulators remain unknown. Our aim was to examine the direct influence of flaxseed extract on basal porcine ovarian functions (proliferation, apoptosis), leptin release, and response to insulin-like growth factor I (IGF-I). First, we examined the effect of flaxseed extract on the accumulation of proliferation (PCNA) and apoptosis (bax) marker and on leptin release in cultured porcine ovarian granulosa cells. Next, granulosa cells were cultured with IGF-I with and without flaxseed extract and analyzed for PCNA and bax accumulation by quantitative immunocytochemistry, whereas leptin was analyzed by RIA. Flaxseeds decreased the accumulation of proliferation marker and increased that of the apoptosis marker at all doses and reduced leptin output at 100 µg/ml. On the contrary, IGF-I promoted PCNA and suppressed bax. Flaxseed did not modify IGF-I action on these parameters. Thus, we showed flaxseed action on porcine reproductive processes, with a direct effect on the ovary and flaxseed ability to affect ovarian cell proliferation, apoptosis, and leptin release. Furthermore, we confirmed the pro-proliferating and anti-apoptosis action of IGF-I, but indicated that flaxseed action on ovarian cell proliferation and apoptosis are not due to changes in their response to IGF-I. The potential direct anti-reproductive action of flaxseed needs to be confirmed properly in in-vivo experiments and thereafter considered during its application in nutrition, medicine, and animal production.
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The objective of the present study was to evaluate the inclusion of corn oil in the diet of sheep and its eect on serum levels of progesterone and estradiol, Twenty-one Pelibuey sheeps were divided into three treatments based on the level of oil included in the diet (T0 = 0, T3 = 3 and T6 = 6% respectively, on dry basis). Blood samples were obtained to determine hormones in serum. Cholesterol and progesterone were higher for T3 and T6 treatments (p < 0.05) compared to T0. Insulin was higher (p < 0.05) in the T6 treatment compared to treatments T3 and T0. At the time of ovulation, estradiol concentration was higher (p < 0.05) for treatments T3 and T6 compared to T0. The inclusion of corn oil in the diet increases the levels of cholesterol, progesterone, estradiol and insulin in sheep hair.
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The effect of ω-3 fatty acid supplementation in the diet on various characteristics of fresh and frozen semen was investigated in Marwari horses. Stallions (6) were fed a standard diet daily from week -13 to week 0 (pre-supplementation phase) followed by supplementation of fish oil, a rich source of n-3 PUFA @64 mg/kg BW from week 1 to 14 (fish oil treatment phase) in diets. Ejaculates were collected from all the stallions on weekly basis from week -5 to 0 and week 9 to 14 during pre-supplementation and fish oil treatment phase, respectively. Effect of n-3 PUFA on ejaculate volume, color and consistency; total and progressive sperm motility, seminal pH, sperm concentration, live sperm and abnormal sperm in fresh semen was non-significant. Similarly, there was no change in the percentage of sperm PTM, HOS reacted sperm, live and abnormal sperm in frozen semen. It was concluded that dietary n-3 PUFA supplementation @64mg/kg BW to horses for 14 weeks did not affect the semen quality. However, the beneficial effects of n-3 PUFA on semen quality may require longer period of supplementation. © 2016, Indian Council of Agricultural Research. All rights reserved.
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The positive effects of fat and energy supplementation on improvements in reproduction are well documented. However, the specific effects of omega-3 polyunsaturated fatty acids (n-3) on reproductive success in ruminants have not been examined in detail. While the link between n-3 and markers associated with reproduction, in particular, prostaglandin F(2α) (PGF(2α)) and the link between PGF(2α) and reproductive outcomes are well established, evidence of a direct effect of high n-3 diets on measurable reproductive outcomes in ruminants is lacking. Therefore, the aim of the current review was to examine the effect of n-3 on a number of reproductive markers and measurable outcomes in sheep and cattle. There is strong evidence linking consumption of diets high in n-3 with reduced circulating peripheral inflammatory markers such as PGF(2α). Inflammatory eicosanoids including PGF(2α), in particular, can significantly affect reproduction outcomes such as the onset of oestrus, embryo survival and parturition. While there is also evidence linking n-3 supplementation with longer time to oestrus and parturition associated with reduced PGF(2α), the effects of n-3 on other measurable outcomes of reproductive success, such as pregnancy rate, embryo survival and intergenerational effects on the health and production of offspring are largely unknown. Similarly, the effects of diets high in n-3 or n-6 polyunsaturated fatty acids on male fertility are also unknown.
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Mammalian cell viability is dependent on the supply of the essential fatty acids (EFAs) linoleic and alpha-linolenic acid. EFAs are converted into omega3- and omega6-polyunsaturated fatty acids (PUFAs), which are essential constituents of membrane phospholipids and precursors of eicosanoids, anandamide and docosanoids. Whether EFAs, PUFAs and eicosanoids are essential for cell viability has remained elusive. Here, we show that deletion of delta6-fatty acid desaturase (FADS2) gene expression in the mouse abolishes the initial step in the enzymatic cascade of PUFA synthesis. The lack of PUFAs and eicosanoids does not impair the normal viability and lifespan of male and female fads2 -/- mice, but causes sterility. We further provide the molecular evidence for a pivotal role of PUFA-substituted membrane phospholipids in Sertoli cell polarity and blood-testis barrier, and the gap junction network between granulosa cells of ovarian follicles. The fads2 -/- mouse is an auxotrophic mutant. It is anticipated that FADS2 will become a major focus in membrane, haemostasis, inflammation and atherosclerosis research.
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Selection in dairy cattle for a higher milk yield has coincided with declined fertility. One of the factors is reduced expression of estrous behavior. Changes in systems that regulate the estrous behavior could be manifested by altered gene expression. This literature review describes the current knowledge on mechanisms and genes involved in the regulation of estrous behavior. The endocrinological regulation of the estrous cycle in dairy cows is well described. Estradiol (E2) is assumed to be the key regulator that synchronizes endocrine and behavioral events. Other pivotal hormones are, for example, progesterone, gonadotropin releasing hormone and insulin-like growth factor-1. Interactions between the latter and E2 may play a role in the unfavorable effects of milk yield-related metabolic stress on fertility in high milk-producing dairy cows. However, a clear understanding of how endocrine mechanisms are tied to estrous behavior in cows is only starting to emerge. Recent studies on gene expression and signaling pathways in rodents and other animals contribute to our understanding of genes and mechanisms involved in estrous behavior. Studies in rodents, for example, show that estrogen-induced gene expression in specific brain areas such as the hypothalamus play an important role. Through these estrogen-induced gene expressions, E2 alters the functioning of neuronal networks that underlie estrous behavior, by affecting dendritic connections between cells, receptor populations and neurotransmitter releases. To improve the understanding of complex biological networks, like estrus regulation, and to deal with the increasing amount of genomic information that becomes available, mathematical models can be helpful. Systems biology combines physiological and genomic data with mathematical modeling. Possible applications of systems biology approaches in the field of female fertility and estrous behavior are discussed.
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The objective of this study was to determine the effects of feeding an increased amount of extruded flaxseed with high proportions of n-3 fatty acids (FA) to transition dairy cows on performance, energy balance, and FA composition in plasma, adipose tissue, and milk fat. Multiparous Israeli-Holstein dry cows (n = 44) at 256 d of pregnancy were assigned to 2 treatments: (1) control cows were fed prepartum a dry-cow diet and postpartum a lactating-cow diet that consisted of 5.8% ether extracts; and (2) extruded flaxseed (EF) cows were supplemented prepartum with 1 kg of extruded flaxseed (7.9% dry matter)/cow per d, and postpartum were fed a diet containing 9.2% of the same supplement. The EF supplement was fed until 100 d in milk. On average, each pre- and postpartum EF cow consumed 160.9 and 376.2g of C18:3n-3/d, respectively. Postpartum dry matter intake was 3.8% higher in the EF cows. Milk production was 6.4% higher and fat content was 0.4% U lower in the EF group than in the controls, with no differences in fat and protein yields. Energy balance in the EF cows was more positive than in the controls; however, no differences were observed in concentrations of nonesterified fatty acids and glucose in plasma. Compared with controls, EF cows had greater proportions of C18:3n-3 in plasma and adipose tissue. The proportion of n-3 FA in milk fat was 3.7-fold higher in the EF cows, and the n-6:n-3 ratio was decreased from 8.3 in controls to 2.3 in the EF cows. Within-group tests revealed that the C18:3n-3 content in milk fat in the EF cows was negatively correlated with milk fat percentage (r = -0.91) and yield (r = -0.89). However, no decrease in de novo synthesis of less than 16-carbon FA was found in the EF group, whereas C16:0 yields were markedly decreased. It appears that the enrichment of C18:3n-3 in milk fat was limited to approximately 2%, and the potential for increasing this n-3 FA in milk is higher for cows with lower milk fat contents. In conclusion, feeding increased amounts of C18:3n-3 during the transition period enhanced dry matter intake postpartum, increased milk production, decreased milk fat content, and improved energy balance. Increased amounts of EF considerably influenced the FA profile of plasma, adipose tissue, and milk fat. However, the extent of C18:3n-3 enrichment in milk fat was limited and was negatively correlated with milk fat content and yield.
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The objectives were to determine the incorporation of dietary encapsulated fats differing in n-6:n-3 ratio into milk fat, plasma, and various ovarian compartments and to examine the effects on ovarian follicular status, preovulatory follicle characteristics, and oocyte quality. Twenty-four multiparous Israeli Holstein cows, averaging 114 d in milk, were assigned to 1 of 3 treatment groups: 1) control (n=7), in which cows were fed a lactating cow diet; 2) E-FLAX (n=8), in which cows were fed a lactating cow diet that consisted of 1kg/d of encapsulated fat (3.8% of dry matter) containing 40.8% flaxseed oil, providing 242.2g of C18:3n-3 (low n-6:n-3 ratio); or 3) E-SUN (n=9), in which cows were fed a lactating cow diet that consisted of 1kg/d of encapsulated fat (3.8% of dry matter) containing 40.8% sunflower oil, providing 260.0g of C18:2n-6 (high n-6:n-3 ratio). Ovaries were monitored by ultrasonography for follicular status, and after synchronization, follicles >7mm were aspirated and evaluated. Ovum pickup was performed (19 sessions for the control and E-FLAX groups and 11 for the E-SUN group), and in vitro maturation and oocyte fertilization were conducted. The E-FLAX treatment increased the proportions of C18:3n-3 (5.8 fold), C20:5n-3, and C22:5n-3 (approximately 4-fold) in milk fat as compared with the other 2 treatments. The proportion of C18:3n-3 fatty acid in plasma increased dramatically with the E-FLAX treatment, from 1.43 and 1.49% in the control and E-SUN groups, respectively, to 7.98% in the E-FLAX group. Consequently, the n-6:n-3 ratio in plasma was reduced from approximately 42 in the control and E-SUN groups to 6.74 in the E-FLAX group. Proportions of C18:3n-3 in follicular fluid and granulosa cells were approximately 5-fold higher in the E-FLAX group than in the other 2 groups. The percentage of C18:2n-6 in cumulus-oocyte complexes of cows in the E-SUN group was 54% higher than that in the E-FLAX group and was 2.4-fold higher than that in the control group; the proportion of C18:3n-3 in the E-FLAX group was 4.73% and was not detected in the other groups. The average numbers of 2- to 5-mm follicles on d 5 and 9 of the cycle were higher in the E-FLAX group than in the E-SUN group, whereas the average numbers of follicles > or =10mm on d 5, 9, and 13 were higher in the E-SUN group than in the other 2 groups. The estrous cycles of the cows were synchronized and PGF(2alpha) was injected on d 16 to 17 of the cycle. The interval from PGF(2alpha) injection to behavioral estrus was longer in the E-FLAX group than in the E-SUN group, and the beginning of the luteal phase of the subsequent cycle was delayed. Concentrations of estradiol in follicular fluid of the preovulatory follicles were higher in the E-SUN group than in the E-FLAX group. The number of follicles aspirated by ovum pickup was higher in the E-FLAX group than in the control group, and the cleavage rate in the E-FLAX group was higher than in the control group, but not the E-SUN group. In conclusion, dietary n-3 fatty acids influenced the follicular status and increased the cleavage rate of oocytes as compared with those of control cows. These findings could be related to modifications of the fatty acid composition in plasma and ovarian compartments in response to dietary supplementation.
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The evidence that omega-3 (n-3) and -6 (n-6) polyunsaturated fatty acids (PUFAs) have differential effects on ovarian function, oocytes and embryo quality is inconsistent. We report on the effects of n-3 versus n-6 PUFA-enriched diets fed to 36 ewes over a 6-week period, prior to ovarian stimulation and follicular aspiration, on ovarian steroidogenic parameters and embryo quality. Follicle number and size were unaltered by diet, but follicular-fluid progesterone concentrations were greater in n-3 PUFA-fed ewes than in n-6 PUFA-fed ewes. The percentage of saturated FAs (mostly stearic acid) was greater in oocytes than in either granulosa cells or plasma, indicating selective uptake and/or de novo synthesis of saturated FAs at the expense of PUFAs by oocytes. High-density lipoproteins (HDLs) fractionated from sera of these ewes increased granulosa cell proliferation and steroidogenesis relative to the FA-free BSA control during culture, but there was no differential effect of n-3 and n-6 PUFAs on either oestradiol or progesterone production. HDL was ineffective in delivering FAs to embryos during culture, although n-6 PUFA HDL reduced embryo development. All blastocysts, irrespective of the treatment, contained high levels of unsaturated FAs, in particular linoleic acid. Transcripts for HDL and low-density lipoprotein (LDL) receptors (SCARB1 and LDLR) and stearoyl-CoA desaturase (SCD) are reported in sheep embryos. HDL reduced the expression of transcripts for LDLR and SCD relative to the BSA control. The data support a differential effect of n-3 and n-6 PUFAs on ovarian steroidogenesis and pre-implantation development, the latter in the absence of a net uptake of FAs.
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Considering the n-3 fatty acids to be partial agonists relative to n-6 fatty acids helps consolidate into a unified interpretation the many diverse reports and controversies on the actions of these two types of essential fatty acids. Some research reports illustrate the similarities between these two types and some emphasize the differences, leaving readers to evaluate the status of n-3 fatty acids from a viewpoint that is conceptually similar to regarding a glass of water as half empty or half full. Both n-3 and n-6 types of fatty acids must be obtained through the diet because they are not synthesized de novo by vertebrates. Both types can support important physiological and developmental processes, can form eicosanoids (prostaglandins, leukotrienes, lipoxins, etc.), can be esterified to and hydrolyzed from tissue glycerolipids, and can be metabolically elongated and desaturated to a variety of highly unsaturated fatty acids. However, some nonesterified n-6 acids are vigorously converted to potent n-6 eicosanoids that exert intense agonist actions at eicosanoid receptors, whereas the n-3 acids less vigorously form n-3 eicosanoids that often produce less intense (partial) actions. Because both types owe their presence in vertebrate tissues to dietary intake, important physiological consequences follow the inadvertent selection of different average daily dietary supplies of these two types of polyunsaturated fatty acids.
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The effect of fat and bovine somatotropin (bST) on preovulatory follicular hormones and lipids was evaluated by feeding cows for 150 d from parturition a control diet, a control diet plus 0.55 kg/d of calcium soaps of fatty acids, or a control diet with 500 mg of bST injected every 14 d. Fourteen days after a synchronized or natural estrus, cows were injected with a PGF2 alpha analogue; 48 h later, follicular fluid from all ovarian follicles > 8 mm was aspirated. Cows fed fat or injected with bST produced more milk and milk solids than did control cows, and cows on the bST treatment lost more body condition after calving than did cows on the other treatments. Both treatments changed the proportion of estradiol-active follicles (> 400 ng of estradiol/ml of follicular fluid) and the correlation between follicular fluid estradiol concentration and the total number large follicles per cow. In follicles aspirated between 60 and 90 DIM the percentage of estradiol-active follicles was 67, 40, and 0 for cows on the control, calcium soaps of fatty acids, and bST treatments, respectively. After 90 DIM, no differences existed between treatments in the percentage of estradiol-active follicles. Estradiol concentration in follicular fluid was correlated with DIM at follicle aspiration (r = 0.51). The proportion of oleic acid in free fatty acids in plasma at 50 DIM was lower in control cows and was lower in follicular fluid of estradiol-active follicles. Both calcium soaps of fatty acids and bST had a considerable effect on follicular development and activity and the composition of fatty acids in follicles.
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Several studies over the past 20 years have demonstrated that subjects on diets composed of substances with high levels of n-3 polyunsaturated fatty acids (PUFAs) (e.g. fish) have a decreased incidence of heart disease. On this basis, a recent report from the Department of Health has advised UK consumers to decrease the proportion of saturated as opposed to unsaturated fats in their diet and to increase the ratio of n-3 to n-6 PUFAs. This could be achieved by altering the amounts of these constituents in milk and meat. n-3 Fatty acids can most easily be added to animal feed as either fish oil or linseed oil and can be increased in the blood and milk of ruminants following protection to avoid hydrogenation in the rumen. In western countries the ratio of consumption of n-6 to n-3 PUFAs is greater than 10 and current evidence tends to suggest that a ratio nearer 5 would be more desirable and compatible with cardiovascular well being. As fertility in the UK dairy herd is already poor, it is important to establish whether alterations in dietary n-3 and n-6 PUFAs affects herd fertility before widespread changes in animal diets are recommended. Therefore, this review considers the role played by PUFAs and eicosanoids in fertility, with particular reference to the implications for farm livestock production.
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Alteration of the polyunsaturated fatty acid (PUFA) composition of milk by dietary supplementation of cows may be beneficial to human health. However, dietary PUFAs may influence synthesis of both prostaglandins and steroid hormones. This study examined the effects of dietary PUFAs on reproductive parameters in lactating cows. Cows were fed an isoenergetic control ration (n = 8) or a diet supplemented with LinPreme (n = 7) or SoyPreme (n = 8). These proprietary feeds are derived from linseed or soybeans and contain high concentrations of linolenic acid (LNA, n-3) or linoleic acid (LA, n-6) protected PUFA, respectively. Both PUFA-supplemented diets reduced plasma progesterone, particularly in the early luteal phase, and increased the number of medium-sized (5-10 mm in diameter) follicles. The diameter of the first dominant follicle, insulin-like growth factor I (IGF-I) concentrations at oestrus and cholesterol concentrations were all higher in cows fed a diet supplemented with LA (n-6) than in cows that did not receive this supplement. In cows fed a diet supplemented with LNA (n-3), there was an increase in oestradiol during the follicular phase. Diet had no effect on non-esterified fatty acid or insulin concentrations, or on the duration of the oestrous cycle. The plasma concentration of 13,14,dihydro-15 keto PGF(2alpha) after administration of 50 iu oxytocin was unaffected by diet on day 15 and day 16 of the oestrous cycle, but showed a greater response on day 17 in the LA (n-6) supplemented group. Therefore, the PUFA content of the diet can influence both ovarian and uterine function in cows. However, further studies using larger numbers of cows are required to test whether fertility is also affected by such diets.
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Increased liver blood flow (LBF) resulting from elevated feed intake in lactating dairy cows may increase steroid metabolism. Continuous infusion of bromosulphthalein (BSP; specifically metabolized in liver) was used to measure LBF. Similarly, progesterone (P4) and estradiol-17beta (E2) were administered by continuous infusion. Circulating concentrations at steady state were used to calculate the metabolic clearance rate (MCR) of BSP, P4, and E2. Experiment 1: Variation in LBF was determined in thee nonlactating and four lactating cows over 3 d at 3 to 5 h after feeding. Coefficients of variation ranged from 14 to 31% among cows within day and from 4 to 8% within cows across days. Experiment 2: Six nonlactating cows were used in a 3 x 3 Latin-square design with three feed regimens: no feed, 0.5 maintenance diet (M), and 1.5 M. Experiment 3: Eight lactating cows were used in a 4 x 4 Latin-square design with four feed regimens: no feed, 0.5 M, 1.5 M, and 2.2 M. In experiments 2 and 3, LBF and MCR of P4 increased immediately after feed consumption and increases persisted longer at higher intakes. The LBF reached a maximum at 2 h after feeding and MCR of P4 reached maximum at 3 h after feeding with a positive correlation (r = 0.92) between LBF and MCR for P4. Experiment 4: A crossover design was used to determine MCR of E2 in unfed or full-fed lactating dairy cows. The MCR of E2 increased immediately after feeding and stayed elevated throughout the 4.5-h infusion period. Thus, LBF and steroid metabolism were acutely elevated by feed consumption in lactating and nonlactating cows. Higher rates of LBF and steroid metabolism in lactating than in nonlactating cows may indicate chronic effects of higher feed intakes as well.
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Four multiparous Holstein cows were used in a 4 x 4 Latin-square design experiment to study the effects of different fat sources on milk production and composition, N utilization, follicular development, and prostaglandin secretion. Cows were fed 4 total mixed rations (TMR) based either on calcium salts of palm oil (Megalac), whole flaxseed, whole sunflower seed, or no supplementary fat (control). Feed intake and digestibilities were generally similar among treatments, except that ether extract digestibility was the lowest for cows fed the control diet. Milk yields were greater for cows fed whole flaxseed and Megalac (32.1 and 31.5 kg/d, respectively) than for those fed sunflower seed and control (25.9 and 24.8 kg/d, respectively). Milk protein concentration was significantly lower for cows fed Megalac (3.68%) compared with those fed flaxseed (3.87%) or control (3.92%). Concentrations of n-3 fatty acids and the n-6 to n-3 fatty acids ratio in milk were the highest and lowest, respectively, for cows fed whole flaxseed. There was an interaction between treatment and time for levels of 13,14-dihydro-15-keto-PGF(2alpha) in plasma; they were greater 30 and 45 min after the oxytocin challenge for cows that were fed sunflower seed compared with those fed either Megalac, flaxseed, or control. Moreover, when concentrations of 13,14-dihydro-15-keto-PGF(2alpha) in plasma were expressed as the area under the overall response curve from 0 to 120 min after the oxytocin injection, it tended to be greater for cows that were fed the sunflower diet compared with those fed either Megalac or flaxseed. In general, follicle dynamics were similar among treatments. These results suggest that feeding diets with high proportions of n-6 fatty acids (61% of total fatty acids for the sunflower seed diet) tended to increase the secretion of series 2 prostaglandins in blood.
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The objective of this trial was to investigate the effects of feeding a soybean oil refining by-product (SORB), made up mainly of sodium salts of long-chain fatty acids, on reproductive performance and productivity of 36 early lactation Holstein cows managed in a free-stall barn or on annual rye-ryegrass pasture. In this 2 x 2 factorial arrangement of treatments, cows consumed 0 or 0.5 kg/d of SORB as part of a total mixed ration for barn cows or as part of a grain supplement fed to cows on intensively, rotationally stocked pasture. Blood was sampled 3 times weekly and plasma was measured for progesterone to assess ovarian activity. Estrus activity was recorded using the HeatWatch estrus detection system. Although average 14-wk milk production (37.2 kg/d) was not different among treatments, barn cows had more persistent lactations than did grazing cows. Cows housed in the barn lost less body weight and returned to initial body weight sooner and had lower mean concentrations of plasma nonesterified fatty acids (464 vs. 261 mEq/L) than those managed on pasture. The milk fat of cows on pasture contained greater proportions of conjugated linoleic acid and linolenic acid but a corresponding 0.22 percentage unit decrease in milk fat concentration (3.39 vs. 3.16%). Cows managed on pasture had greater peak concentrations of plasma progesterone during the first estrous cycle. Cows managed on pasture and fed SORB had the greatest accumulation of plasma progesterone over the 14 wk of the study (SORB x housing interaction). These cows experienced the most mounts during their first estrus (9.3) and pregnancy rate was also greatest for this treatment (62.5%). Feeding SORB did not affect production of milk, fat, or protein. Loss of body condition was less in cows fed SORB. Ruminal fluid concentration of propionate increased and ruminal pH decreased in cows fed SORB. A lower proportion of fatty acids less than 18 carbons in length was found in the milk fat of cows fed SORB, thus indicating lower de novo synthesis of fatty acids. Higher proportions of C18:2n-6 and conjugated C18:2 were found in the milk fat of cows fed SORB. Based on concentrations of plasma progesterone, cows fed SORB experienced their first ovulation earlier (26.7 vs. 42.4 d postpartum) than did cows not supplemented with SORB. Neither housing system nor SORB supplementation influenced detection of first estrus (50.5 d) or the mean length of each estrus period (447 min).
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To investigate the pharmacokinetic interaction between cyclosporin A (CsA) and docosahexaenoic acid (DHA) in vivo, 5 mg/kg CsA was orally or intravenously coadministered with DHA (50-200 microg/kg) to rats. The effect of DHA on CYP3A activity was determined using rat liver microsomes in vitro. Moreover, the effect of DHA on P-glycoprotein (P-gp) function was examined using cultured Caco-2 cells in vitro. After oral coadministration of CsA with 100 microg/kg and 200 microg/kg DHA, bioavailability (BA) was significantly increased, compared with control rats. In contrast, no pharmacokinetic interaction was observed when CsA was intravenously administered in rats dosed orally with DHA, suggesting that DHA did not affect hepatic metabolism. The formation of 6beta-hydroxytestosterone from testosterone in rat liver microsomes was competitively inhibited by DHA. The Km, Vmax, and Ki values were 25.5 microM, 2.45 nmol/min/mg protein, and 5.52 microM, respectively. Moreover, basal-to-apical transport of [3H]CsA in the Caco-2 cell monolayer was not affected by DHA but was decreased by valspodar (PSC 833), a P-gp inhibitor. Our finding is the first to indicate that DHA inhibits intestinal CYP3A both in vitro and in vivo, but not P-gp. It was thus demonstrated that DHA could be used as a BA enhancer for the drugs that are extensively metabolized by CYP3A in the gut.
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In Westernized societies, average consumption of n-6 polyunsaturated fatty acids (PUFAs) far exceeds nutritional requirements. The ratio of n-6 to n-3 PUFAs is generally >10:1 whereas on a primitive human diet it was closer to 1:1. Diets fed to intensively farmed livestock have followed a similar trend. Both n-6 and n-3 PUFAs can influence reproductive processes through a variety of mechanisms. They provide the precursors for prostaglandin synthesis and can modulate the expression patterns of many key enzymes involved in both prostaglandin and steroid metabolism. They are essential components of all cell membranes. The proportions of different PUFAs in tissues of the reproductive tract reflect dietary consumption. PUFA supplements (particularly n-3 PUFAs in fish oil) are promoted for general health reasons. Fish oils may also benefit fertility in cattle and reduce the risk of preterm labor in women, but in both cases current evidence to support this is inconclusive. Gamma-linolenic acid containing oils can alter the types of prostaglandins produced by cells in vitro, but published data to support claims relating to effects on reproductive health are lacking. Spermatozoa require a high PUFA content to provide the plasma membrane with the fluidity essential at fertilization. However, this makes spermatozoa particularly vulnerable to attack by reactive oxygen species, and lifestyle factors promoting oxidative stress have clear associations with reduced fertility. Adequately powered trials that control for the ratios of different PUFAs consumed are required to determine the extent to which this aspect of our diets does influence our fertility.
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Ovarian estrogen exerts both positive and negative feedback control over luteinizing hormone (LH) secretion during the ovulatory cycle. Estrogen receptor (ER) α but not ERβ knockout mice lack estrogen feedback. Thus, estrogen feedback appears to be primarily mediated by ERα. However, it is now recognized that, in addition to binding to estrogen response elements (EREs) in DNA to alter target gene transcription, ERα signals through ERE-independent or nonclassical pathways, and the relative contributions of these pathways in conveying estrogen feedback remain unknown. Previously we created a knockin mouse model expressing a mutant form of ERα (AA) with ablated ERE-dependent but intact ERE-independent activity. Breeding this allele onto the ERα-null (−/−) background, we examine the ability of ERE-independent ERα signaling pathways to convey estrogen feedback regulation of the female hypothalamic–pituitary axis in vivo. ERα−/AA exhibited 69.9% lower serum LH levels compared with ERα−/− mice. Additionally, like wild type, ERα−/AA mice exhibited elevated LH after ovariectomy (OVX). Furthermore, the post-OVX rise in serum LH was significantly suppressed by estrogen treatment in OVX ERα−/AA mice. However, unlike wild type, both ERα−/AA and ERα−/− mice failed to exhibit estrous cyclicity, spontaneous ovulation, or an afternoon LH surge response to estrogen. These results indicate that ERE-independent ERα signaling is sufficient to convey a major portion of estrogen's negative feedback actions, whereas positive feedback and spontaneous ovulatory cyclicity require ERE-dependent ERα signaling. • neuroendocrine • reproduction
Article
Fats in the diet can influence reproduction positively by altering both ovarian follicle and corpus luteum function via improved energy status and by increasing precursors for the synthesis of reproductive hormones such as steroids and prostaglandins. Dietary fatty acids of the n-3 family reduce ovarian and endometrial synthesis of prostaglandin F2alpha, decrease ovulation rate in rats and delay parturition in sheep and humans. Polyunsaturated fatty acids such as linoleic, linolenic, eicosapentaenoic and docosahexaenoic acids may inhibit prostaglandin F2alpha synthesis through mechanisms such as decreased availability of its precursor arachidonic acid, an increased competition by these fatty acids with arachidonic acid for binding to prostaglandin H synthase, and inhibition of prostaglandin H synthase synthesis and activity. It is not known whether polyunsaturated fatty acids regulate expression of candidate genes such as phospholipase A2 and prostaglandin H synthase via activation of nuclear transcription factors such as peroxisome proliferator-activated receptors. Manipulation of the fatty acid profile of the diet can be used potentially to amplify suppression of uterine synthesis of prostaglandin F2alpha during early pregnancy in cattle, which may contribute to a reduction in embryonic mortality. Feeding fats and targeting of fatty acids to reproductive tissues may be a potential strategy to integrate nutrition and reproductive management to improve animal productivity.
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Inadequate dietary energy intake and poor body condition are two of the most pervasive factors influencing reproductive ef- ficiency in beef cattle production systems. Therefore, an important goal has been to discover novel methods for enhancing repro- ductive processes in cattle that are exposed to these conditions, often on a repeated basis. This review will examine dietary fat as a reproductive "nutraceutical," including the role of fatty acid content and minimum effective intake. Although the consumption of neutral lipids by ruminants is limited under natural conditions, the addition of digestible fats to increase caloric content or to positively modify diet physical characteristics is a long-standing practice. More recently, fat supplements have been used in at- tempts to influence specific metabolic pathways and, ultimately, hormones that directly modulate ovarian cellular processes. The basis for this approach lies within an array of digestive, metabolic, and reproductive sequelae that occur when cattle consume significant quantities of digestible fat. Evidence suggests that the consumption of fat by cattle, particularly polyunsaturated plant oils, can positively influence ovarian follicular growth, luteal function, and postpartum reproductive performance independent of caloric effects. Mechanistically, these effects have been attributed to a cascade of events that change rumen fermentation pat- terns, heighten lipoprotein-cholesterol synthesis, increase secretion of ovarian steroids, modify circulating concentrations of insulin and GH, and enhance the synthesis or accumulation of IGF-I in ovarian cells. Whole oilseeds, oil milling by-products, and some manufactured products are available to exploit these physiological concepts.
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Cattle are fed moderate amounts of long chain fatty acids (FA) with the objective to enhance lactation and growth; however, recent interest on lipid feeding to cows has focused on reproduction, immunity and health. Increasing the caloric density of the ration by fat feeding has generally improved measures of cow reproduction, but when milk yield and body weight losses were increased by fat supplementation, positive effects on reproduction were not always observed. Feeding fat has influenced reproduction by altering the size of the dominant follicle, hastening the interval to first postpartum ovulation in beef cows, increasing progesterone concentrations during the luteal phase of the oestrous cycle, modulating uterine prostaglandin (PG) synthesis, and improving oocyte and embryo quality and developmental competence. Some of these effects were altered by the type of FA fed. The polyunsaturated FA of the n-6 and n-3 families seem to have the most remarkable effects on reproductive responses of cattle, but it is not completely clear whether these effects are mediated only by them or by other potential intermediates produced during rumen biohydrogenation. Generally, feeding fat sources rich in n-6 FA during late gestation and early lactation enhanced follicle growth, uterine PG secretion, embryo quality and pregnancy in cows. Similarly, feeding n-3 FA during lactation suppressed uterine PG release, and improved embryo quality and maintenance of pregnancy. Future research ought to focus on methods to improve the delivery of specific FA and adequately powered studies should be designed to critically evaluate their effects on establishment and maintenance of pregnancy in cattle.
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Some studies have reported improved reproductive performance with dietary fat supplementation. This study examined effects of fatty acids with different lengths, or desaturation, or both, on metabolism of estradiol (E2) and progesterone (P4) in bovine liver slice incubations (experiments 1 and 2) and in vivo (experiment 3). In experiment 1, effects of fatty acids C16:0 (palmitic acid), C16:1 (palmitoleic acid), C18:1 (oleic acid), and C18:3 (linolenic acid) were evaluated at 30, 100, and 300 microM on P4 and E2 metabolism in vitro. In experiment 2, stearic acid (C18:0) and C18:3 were evaluated in the same incubation conditions. In experiment 1, all of the fatty acids had some significant inhibitory effect on metabolism of P4, E2, or both (300 microM C16:0 on E2; 100 microM C16:1 on E2; 300 microM C16:1 on both P4 and E2; 300 microM C18:1 on P4; and 100 and 300 microM C18:3 on both P4 and E2). In experiment 2, C18:3 (100 and 300 microM) but not C18:0 decreased P4 and E2 metabolism. Overall, the most profound increase (approximately 60%) in half-life of P4 and E2 was observed with incubations of 300 microM C18:3 in both in vitro experiments. Based on these in vitro results, in experiment 3 linseed oil (rich in C18:3) was supplemented into the abomasum and acute effects on metabolism of E2 and P4 were evaluated. Cows (n=4) had endogenous E2 and P4 minimized (corpus luteum regressed, follicles aspirated) before receiving continuous intravenous infusion of E2 and P4 to analyze metabolic clearance rate for these hormones during abomasal infusion of saline (control) or 70 mL of linseed oil every 4h for 28h. Linseed oil infusion increased C18:3 in plasma by 46%; however, metabolic clearance rate for E2 and P4 were similar for control cows compared with linseed-treated cows. Thus, in vitro experiments indicated that E2 and P4 metabolism can be inhibited by high concentrations of C18:3. Nevertheless, in vivo, linseed oil did not acutely inhibit E2 and P4 metabolism, perhaps because insufficient C18:3 concentrations (increased to approximately 8 microM) were achieved. Further research is needed to determine the mechanism(s) of fatty acid inhibition of P4 and E2 metabolism and to discover practical methods to mimic this effect in vivo.
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Ovulation is a prostaglandin (PG)-dependent process. Although n-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) have differing effects in the body, both reduce PG synthesis. We hypothesized that dietary n-3 fatty acids and CLA would differentially alter ovarian PG profiles through reductions in expression of enzymes involved in PG biosynthesis resulting in enhanced ovulation. Our objectives were to determine how dietary stearidonic acid and eicosapentaenoic acid (EPA) at 0.3 g/100 g diet and mixed isomers of CLA at 0.7 g/100 g diet, human achievable levels with daily consumption of fish or beef and dairy products, respectively, would influence ovulation and ovarian cyclooxygenase-1 (COX-1) and COX-2 expression in ovulation-induced rats. After 27 days on diet and ovulation induction, ovaries were isolated and analyzed from 22 pups per diet. Eicosapentaenoic acid ingestion reduced ova release by 16% while increasing PGE(2) and PGF(2alpha) release without altering COX-1 or COX-2 expression. Conversely, ovarian COX-1 expression was increased 135% with stearidonic acid ingestion associated with increased PGF(2alpha) without altering PGE(2) or ova release. Conjugated linoleic acid ingestion reduced COX-2 expression to 65% of that in rats consuming control and EPA diets; however, without affecting ovulation or PGs. Although it is generally believed that the COX-2 is the primary COX involved in ovulation, these results demonstrated that the n-3 PUFA differently affect ovarian COX-1 expression and that this effect differs from CLA, which reduced COX-2 expression. Further, although ovarian PGF(2alpha) is the primary PG altered by dietary n-3 PUFA, n-3 PUFA differentially influence ovarian PG biosynthesis and can decrease ova release, possibly induced through constitutive COX-1 enzyme expression.
Article
Medial basal hypothalamic (MBH) and median eminence (ME) fragments from male rats were incubated in Krebs-Ringer bicarbonate-glucose buffer, pH 7.4, at 37°C and the prostaglandin Es (PGEs) released into the medium were measured by RIA. Basal release of PGE by the ME was 5-6 times greater than that by the MBH. However, if the ME was not separated from the MBH, the release of PGE by the MBH-ME unit was similar to that of the MBH alone. In vivo treatment with indomethacin (Id;[1-(p-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetic acid]) to inhibit PG synthesis (single sc injection, 2.5 mg/100 g BW, 24 h before) decreased the basal release of PGEs by MBH and ME by about 50%. In vitro addition of Id (100 μM) almost completely suppressed basal release of PGEs by both the MBH and ME. Basal release of LHRH by the ME was also significantly depressed by Id. Incubation of the tissues with norepinephrine (NE) at doses (6-600 μM) which increased LHRH output also elicited PGE release. Although dopamine (DA) also released LHRH, it was less effective than NE in inducing PGE release. As reported earlier for LHRH, the quantity of PGEs released by the ME in response to the catecholamines was greater than that released by the MBH. Incubation of ME with different concentrations of PGE2 evoked LHRH release; the maximal effect was observed with the 0.28-μM dose. Only this dose stimulated LHRH release by the MBH. Incubation of MBH or ME with PGF(2α) (0.028-2.8 μM) failed to induce LHRH release. In vitro suppression of PG synthesis with Id completely abolished the release of LHRH by the ME induced by DA or NE (60 μM). However, release of LHRH induced by PGE2 (2.8 μM) was not affected by the inhibitor. The results indicate that DA and, particularly, NE can stimulate PGE release by the MBH and, especially, by the ME and that PGE2 acts mainly at the ME to evoke LHRH release. In addition, they suggest that 1) the stimulatory effect of both catecholamines on LHRH release is mediated by prostaglandins, and 2) catecholamines and PGE2 can stimulate LHRH release by acting on the ME terminals of LHRH-secreting neurons.
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Improved reproductive performance and reduced incidence of metabolic disorders have been postulated to be benefits of feeding supplemental fat to dairy cows. Increased plasma nonesterified fatty acid concentrations during fat supplementation may result from incomplete tissue uptake of fatty acids after lipoprotein lipase hydrolysis of very-low-density lipoprotein triglyceride; however, evidence suggests that net adipose tissue triglyceride hydrolysis may be increased during fat supplementation. Plasma 3-OH-butyrate concentrations remain relatively constant during fat supplementation but may have a tendency to be reduced if fat is supplemented to cows having relatively high basal plasma 3-OH-butyrate concentrations. Because plasma ketone levels usually increase when nonesterified fatty acid concentrations are elevated, it is hypothesized that potential antiketogenic effects of added fat are due to a glucose sparing effect. Supplemental fat does not seem to reduce hepatic lipid infiltration near the time of calving. Potential mechanisms by which supplemental fat may improve reproductive performance include stimulation of prostaglandin F2 a synthesis and secretion and enhanced utilization of blood cholesterol for progesterone synthesis. Days postpartum until first ovulation and luteal function of dairy cattle have been related to energy balance during the first 3 wk postpartum. Energy balance data for early lactation cows fed supplemental fat are not plentiful; however, slight but statistically nonsignificant increases have been observed when feeding fat. Cows fed supplemental fat that experience improved energy balance may begin to cycle sooner because of enhanced follicular growth and development. Applied studies examining the effects of supplemental fat on reproductive performance have provided inconsistent results.
Article
This chapter describes dietary polyunsaturated fatty acids and eicosanoid formation in humans. The enzymatic processes responsible for both the desaturation and the elongation of fatty acids are located in the microsomal fraction, mainly of the liver. In healthy humans the desaturation of the parent n-6 and n-3 polyunsaturated fatty acids, linoleic and α-linolenic acids, to the derivative fatty acids, seems to proceed slowly and ineffectively, whereas the steps of elongation are in general more rapid. A large excess of a fatty acid from one family in the diet may furthermore inhibit the desaturation of smaller amounts of a fatty acid from another family, as the enzymes of desaturation and elongation are shared among all families. Also, the presence of 22-carbon polyunsaturated fatty acids shows an inhibitory effect on the initial conversion steps of linoleic and α-linolenic acids. Dietary eicosapentaenoic acid is not incorporated into the phosphatidylinositol of human platelets in vivo, whereas in vitro this class of phospholipids incorporates eicosapentaenoic acid. Human endothelial cell cultures do not transform exogenous eicosapentaenoic acid into prostaglandin I3, whereas prostaglandin I3 is formed in humans but not rats after dietary eicosapentaenoic acid. Therefore, suggestions concerning dietary fatty acids and eicosanoid formation in humans emerging from animal experiments or from in vitro studies should be considered with the utmost care.
Article
The present study attempts to elucidate the possible role of adenosine 3',5'-monophosphate (cAMP) and prostaglandin E2 (PGE2) in the function of the neural luteinizing hormone-releasing hormone (LH-RH) apparatus. To this end, in vitro LH-RH release from superfused hypothalamic fragments and cAMP production by hypothalamic P2 membrane fractions were measured. Immature female rats (day 28) were ovariectomized and implanted with Silastic capsules containing estradiol (235 micrograms/ml). Two days later, animals were sacrificed and the mediobasal hypothalamic preoptic area (hypothalamic units or fragments) were removed. To examine in vitro LH-RH release from superfused hypothalamic fragments, effluents were collected into tubes on ice at 10-min intervals and LH-RH concentration was determined by radioimmunoassay (RIA). Following a 50-min control period, a step-wise increment in several doses of PGE2 (each dose for a 50-min interval) evoked a dose-related increase in LH-RH release. PGE2 induced significant (P less than 0.01) increments in LH-RH release at doses of 5.68 X 10(-7), 5.68 X 10(-6), and 5.68 X 10(-5) M, respectively. When adenylate cyclase activators, such as forskolin and cholera toxin were infused in a step-wise manner (each dose for a 50-min interval) following a 50-min control period, a dose-related increase in LH-RH release was also obtained; forskolin and cholera toxin significantly (P less than 0.01) stimulated LH-RH release at doses of 1 X 10(-4) and 5.4 X 10(-10) M, respectively. These two substances were ineffective in stimulating LH-RH release when hypothalamic fragments were superfused in calcium-free plus EGTA (10 mM) containing medium.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
Dose-response relationships have been suggested for the role of estradiol (E2) in the induction of both the LH surge and estrous behavior in the ewe. However, it is not always clear whether it is the amount of E2 or the length of time that E2 is present that is important. Furthermore, in previous studies, the intensity of sexual behavior has rarely been studied quantitatively. Our aims in this work were to analyze in more detail the effects of two injected doses of estradiol benzoate (25 or 50 micrograms) for the induction of both the LH surge and estrous behavior (experiment I) and to dissociate the roles of quantity and duration of presence of E2 as administered by implants (experiment II). Increasing the dose of E2 in both experiment I and experiment II decreased the latency to onset of both the LH surge and the receptivity. The duration of E2 presence marginally affected the latency of both responses and the duration of the LH surge. By contrast, the duration of receptivity depended largely on the duration of E2 presence (experiment II: r = 0.569, P < 0.01). This result explains the dose-duration effect mentioned previously in the literature and found in experiment I. The maximum response increased with dose in both experiment I and experiment II for receptivity and only in experiment I for the LH surge. We conclude that, at estrus, E2 acts in a similar fashion to induce receptive behavior and the LH surge but controls the maximum levels and the duration of these endocrine and behavioral responses differently.
Article
The effects of different ratios of dietary (n-3):(n-6) polyunsaturated fatty acids on prostaglandin E, prostaglandin F2 alpha and ovulation in rats were assessed. Dietary (n-3) polyunsaturated fatty acids were incorporated, by ovarian phospholipids with ovarian tissue enrichment, with (n-3) polyunsaturated fatty acids enhancing, and (n-6) polyunsaturated fatty acids reducing, the number of ova released in immature rats primed with pregnant mares' serum gonadotrophin and human chorionic gonadotrophin. Incorporation of (n-3) polyunsaturated fatty acids appeared to enhance ovulation by altering total prostaglandin E production. This effect may be induced by changes in the prostaglandin E3:E2 ratio and the synthesis of less biologically active prostaglandin E3, or by dilution of the anti-ovulatory properties attributable to prostaglandin E2. High incorporation of dietary (n-6) polyunsaturated fatty acids may lead to reduced ovulation through excessive production of prostaglandin E2. Prostaglandin E or F2 alpha and alterations in tissue phospholipid composition inhibited progesterone release, and inhibition was independent of the series of prostaglandin produced. This study provides evidence that dietary lipids affect ovulation in rats with possible implications for reproduction in other vertebrates.
Article
Fat supplementation (about 3% of dietary dry matter) has often positively influenced the reproductive status of the dairy cow, including increased size of the ovulatory follicle, increased numbers of ovarian follicles, increased plasma concentration of progesterone, reduced secretion of prostaglandin metabolite, increased lifespan of the corpus luteum, and improved fertility. Supplemental fat may allay partially negative energy status during the early postpartum period, yet often the positive reproductive influence of supplemental fat has been independent of the energy status of the cow. The fatty acid profile of supplemental fats is influential to their impact. Linoleic acid and eicosapentaenoic acid (found in fish meal) are proven inhibitors of cyclooxygenase in endometrial tissue of dairy cows. As a result, endometrial secretion of PGF alpha can be suppressed, thus potentially preventing early embryonic death. This process may be aided by the effect fat has in suppressing estradiol-17 beta secretion, thus reducing uterine PGF2 alpha secretion and decreasing the sensitivity of the corpus luteum to PGF2 alpha. Targeting of dietary fatty acids toward ovarian and uterine function may enhance efficiency of reproductive management and fertility.
Article
Fats in the diet can influence reproduction positively by altering both ovarian follicle and corpus luteum function via improved energy status and by increasing precursors for the synthesis of reproductive hormones such as steroids and prostaglandins. Dietary fatty acids of the n-3 family reduce ovarian and endometrial synthesis of prostaglandin F2alpha, decrease ovulation rate in rats and delay parturition in sheep and humans. Polyunsaturated fatty acids such as linoleic, linolenic, eicosapentaenoic and docosahexaenoic acids may inhibit prostaglandin F2alpha synthesis through mechanisms such as decreased availability of its precursor arachidonic acid, an increased competition by these fatty acids with arachidonic acid for binding to prostaglandin H synthase, and inhibition of prostaglandin H synthase synthesis and activity. It is not known whether polyunsaturated fatty acids regulate expression of candidate genes such as phospholipase A2 and prostaglandin H synthase via activation of nuclear transcription factors such as peroxisome proliferator-activated receptors. Manipulation of the fatty acid profile of the diet can be used potentially to amplify suppression of uterine synthesis of prostaglandin F2alpha during early pregnancy in cattle, which may contribute to a reduction in embryonic mortality. Feeding fats and targeting of fatty acids to reproductive tissues may be a potential strategy to integrate nutrition and reproductive management to improve animal productivity.
Article
In a survey on pregnancy rate and embryonic losses in dairy cattle on 6 Israeli farms, cows (n = 78) were divided into 3 groups on the basis of ultrasonography at 21 d post insemination; pregnancy diagnosis at 40 to 50 d post insemination and blood progesterone (P4) levels at 21 d. The groups were either pregnant (P4 level > 1.0 ng/ mL); not pregnant (P4 < 0.5 ng/mL), or showed early embryo loss (P4 > 1.0 ng/mL and the presence of an embryonic vesicle on D 21 but later returned to estrus or were found not pregnant on D 40 to 50). On the day of insemination, peripheral estrogen was significantly higher (P < 0.05) in the early embryo loss group (15.3 +/- 1.1 pg/mL, n = 27) than in pregnant (9.4 +/- 0.6 pg/mL, n = 26) or not pregnant (9.6 +/- 0.7 pg/mL, n = 25) group. The cows on 3 farms which were fed 1 to 2 kg/d of vetch (Vicia sativa), an estrogenic legume, had higher estrogen concentrations on the day of insemination than cows (2 farms) fed other legumes (13.7 +/- 0.64, n = 58 vs 10.7 +/- 0.8 pg/mL, n = 42; P < 0.01). On one of the 3 farms, vetch was replaced with alfalfa after the first year. Following the cessation of vetch feeding the estrogen concentrations in the blood decreased from 32 +/- 5 pg/mL to 14 +/- 2 pg/mL (n = 9). These data suggest that high peripheral estrogen on the day of insemination is associated with early embryonic loss. These data also indicate that estrogen concentrations on the day of insemination can be influenced by diet.
Article
Ultrasound-mediated intrafollicular injection and aspiration procedures were used to investigate the ability of the selective cyclooxygenase-2 inhibitor, NS-398, to inhibit intrafollicular PGE2 synthesis and suppress ovulation in dairy cattle. Follicular growth and timing of the preovulatory gonadotropin surge were synchronized in 55 Holstein cows and the position of the ovulatory follicle was determined by daily ultrasound scanning. Preovulatory follicular fluid was aspirated from the largest follicle in four animals at 0, 6, 12, 18, and 24 h after GnRH injection (n = 20). The remaining 35 animals were subjected to ultrasound-mediated intrafollicular injection of NS-398 (10 microM final concentration; n = 19) or diluent (n = 16; controls). At 24 h after GnRH injection, follicular fluid was harvested from a subset of NS-398- (n = 9) and diluent-treated animals (n = 6). The remaining NS-398- and diluent-treated animals were subjected to ultrasonography every 6 h for 36 h after intrafollicular injection, and then daily through d 7 of the subsequent luteal phase to monitor ovulation and corpus luteum development. Follicular fluid PGE2 concentrations were increased following GnRH injection and reached a maximum at 24 h (P < 0.05). Follicular fluid PGE2 concentrations were decreased in NS-398- vs. diluent-treated follicles (7.2 vs. 52.2 ng/mL respectively; P < 0.05), but progesterone concentrations did not differ. Intrafollicular injection of NS-398 also inhibited follicle rupture (P < 0.001). All 10 control animals ovulated within 30 h of GnRH injection. Nine out of the ten NS-398-injected animals failed to ovulate. The NS-398-injected follicles developed morphological and endocrine characteristics resembling luteinized, unruptured follicles. Thus, intrafollicular PGE2 synthesis and follicle rupture, but not luteinization, were inhibited in cattle following ultrasound-mediated intrafollicular injection of NS-398. Ultrasound-mediated intrafollicular injection of NS-398 is a useful tool for mechanistic studies of intrafollicular regulation of the ovulatory process in cattle.
Article
Four lactating Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square design to determine the effects of feeding micronized and extruded flaxseed on milk composition and blood profile in late lactation. Four diets were formulated: a control (C) diet with no flaxseed, a raw flaxseed (RF) diet, a micronized flaxseed (MF) diet, and an extruded flaxseed (EF) diet. Flaxseed diets contained 12.6% flax-seed (dry matter basis). Experimental periods consisted of 21 d of diet adaptation and 7 d of data collection. Feeding flaxseed reduced milk yield and energy-corrected milk by 1.8 and 1.4 kg/d, respectively. Yields of milk protein and casein were also lower for cows fed flaxseed diets than for those fed the C diet. Milk yield (1.6 kg/d) and milk fat percentage (0.4 percentage unit) were lower for cows fed EF than those fed MF. Plasma cholesterol and nonesterified fatty acid concentrations were higher for cows fed flaxseed diets relative to those fed the C diet. Flaxseed supplementation decreased plasma concentrations of medium-chain (MCFA) and saturated (SFA) fatty acids and increased concentrations of long-chain (LCFA) and monounsaturated fatty acids. Feeding flaxseed reduced the concentrations of short-chain fatty acids (SCFA), MCFA, and SFA in milk fat. Consequently, concentrations of LCFA and unsaturated fatty acids were higher for cows fed flaxseed diets than for those fed the C diet. Flaxseed supplementation increased average concentrations of C(18:3) and conjugated linoleic acid by 152 and 68%, respectively. Micronization increased C(18:3) level, and extrusion reduced concentrations of SCFA and SFA in milk. It was concluded that feeding raw or heated flaxseed to dairy cows alters blood and milk fatty acid composition. Feeding extruded flaxseed relative to raw or micronized flaxseed had negative effects on milk yield and milk composition.
Article
Hormonal effects on behaviours in animals and humans are now well enough understood for general statements about causal steps to be proposed. Facilitation or repression of a given behaviour by a given hormone can depend on the person's genetic and developmental history, on the temporal and spatial parameters of the hormone's administration, on the hormone's metabolism and on the specific receptor isoform available in a given neuron. The gene for oestrogen receptor-alpha is required for an entire chain of behaviours essential for reproduction, from courtship through maternal behaviours. In order to show that it is possible to use endocrine tools to explain a mammalian behaviour, we analysed lordosis behaviour neuronal circuitry as well as the molecular mechanisms of its facilitation by oestrogens. The functional genomics of oestrogenic effects on lordosis arrange themselves in modules for neuronal Growth, Amplification (by progestins), Preparatory behaviours, Permissive actions by hypothalamic neurons, and Synchronization of mating behaviour with ovulation (GAPPS). A related four-gene micronet involving the amygdala and the paraventricular nucleus of the hypothalamus supports social recognition. Underlying all sociosexual behaviour is the fundamental arousal of brain and behaviour. Elementary arousal depends on a bilateral, bidirectional system universal among mammalian brains, and it can be altered by null deletion of the gene for oestrogen receptor-alpha. Future molecular and biophysical studies will specify how hormone effects in the brain change central nervous system state in such a manner as to alter the frequencies of entire sets of behavioural responses.
Article
This manuscript focuses on potential changes in reproductive physiology that occur due to high milk production in lactating dairy cows. Four reproductive measures are discussed: interval to first ovulation, conception rate, duration of estrus, and multiple ovulation rate. The last two responses have now been closely linked to level of milk production. In contrast, time to first ovulation does not appear to be associated with level of milk production, and the association of conception rate with level of milk production is still controversial. In an attempt to explain some of the changes in reproductive physiology caused by high milk production a model of elevated steroid metabolism in lactating dairy cows is presented. Although many aspects of this model remain to be tested, a central role for elevated steroid metabolism in lactation-induced reproductive changes seems likely.
Article
The objective of this study was to determine if there is an association between level of milk production and duration of estrus as determined by standing activity recorded by a radiotelemetry system. Holstein cows (n = 267; 50 DIM) were fitted with a transmitter that allowed continuous recording of standing activity. Cows were housed in a free-stall barn and milked twice daily. Ovulation was confirmed for all estruses (n = 380). Average milk production for the 10 days before the day of estrus was used to classify cows as lower (< 39.5 kg/day) or higher (>/= 39.5 kg/day) producers at the time of estrous expression. Follicle size and serum estradiol (E(2)) concentrations were determined in a subset of cows (n = 71) on the day of estrus. Duration (6.2 +/- 0.5 h versus 10.9 +/- 0.7 h; P < 0.0001), standing events (6.3 +/- 0.4 versus 8.8 +/- 0.6; P = 0.001), and standing time (21.7 +/- 1.3 s versus 28.2 +/- 1.9 s; P = 0.007) were shorter for estruses from higher (46.4 +/- 0.4 kg/day; n = 146) than lower producers (33.5 +/- 0.3 kg/day; n = 177). Milk production was correlated with the duration of estrus (r = -0.51; P < 0.0001; n = 323). Higher producers had lower E(2) concentrations than lower producers (6.8 +/- 0.5; n = 31 versus 8.6 +/- 0.5 pg/ml; n = 40; P = 0.01) in spite of larger pre-ovulatory follicle diameter (18.6 +/- 0.3; n = 31 versus 17.4 +/- 0.2 mm; n = 40; P 0.004). Interestingly, E(2) concentrations were not correlated with diameter of the pre-ovulatory follicle (r = -0.17; P = 0.15) but milk production was correlated with both E(2) concentrations (r = -0.57; P < 0.0001) and diameter of the pre-ovulatory follicle (r = 0.45; P < 0.0001). Thus, high milk production decreases duration of estrus probably due to decreased circulating concentrations of E(2).
Article
The inhibitory effect of saturated fatty acids (SFAs): palmitic acid (PA), stearic acid (SA) and polyunsaturated fatty acids (PUFAs): linoleic acid (LA), linolenic acid (LN), arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on six human drug-metabolizing enzymes (CYP1A2, 2C9, 2C19, 2D6, 2E1 and 3A4) was studied. Supersomes from baculovirus-expressing single isoforms were used as the enzyme source. Phenacetin O-deethylation (CYP1A2), diclofenac 4-hydroxylation (CYP2C9), mephenytoin 4-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1) and midazolam 1-hydroxylation (CYP3A4) were used as the probes. Results show that all the five examined PUFAs competitively inhibited CYP2C9- and CYP2C19-catalyzed metabolic reactions, with Ki values ranging from 1.7 to 4.7 microM and 2.3 to 7.4 microM, respectively. Among these, AA, EPA and DHA tended to have greater inhibitory potencies (lower IC(50) and Ki values) than LA and LN. In addition, these five PUFAs also competitively inhibited the metabolic reactions catalyzed by CYP1A2, 2E1 and 3A4 to a lesser extent (Ki values>10 microM). On the other hand, palmitic and stearic acids, the saturated fatty acids, had no inhibitory effect on the activities of six human CYP isozymes at concentrations up to 200 microM. Incubation of PUFAs with CYP2C9 or CYP2C19 in the presence of NADPH resulted in the decrease of PUFA concentrations in the incubation mixtures. These results indicate that the PUFAs are potent inhibitors as well as the substrates of CYP2C9 and CYP2C19.
Article
Reproductively normal crossbred beef heifers were individually offered a diet of barley straw and concentrate supplemented with one of four levels of a fish oil (FO) enriched supplement. Following oestrous cycle synchronisation, blood samples were collected at appropriate intervals for the measurement of progesterone (P(4)), oestradiol (E(2)), fatty acids, insulin-like growth factor 1 (IGF-1) and metabolites. On days 15 and 16 of the cycle, oxytocin was administered intravenously and the prostaglandin F(2alpha) (PGF(2alpha)) response was measured as venous concentrations of 13,14-dihydro-15-keto PGF(2alpha) (PGFM). The heifers were slaughtered on days 17 or 18 of the oestrous cycle and endometrial tissue, rumen fluid and follicular fluid were collected for determination of fatty acid concentrations. In general there was no effect (P>0.05) of diet on plasma P(4) or E(2) concentrations. Increasing FO supplementation increased CL diameter on day 7 post-oestrus (P<0.0001) but had no effect on diameter on day of slaughter (P>0.05). On day 15, PGFM concentration was greater on the highest level of FO supplementation compared to controls (P<0.05), however, there were no differences between other diet comparisons (P>0.05). There was no effect of diet on PGFM concentration on day 16 (P>0.05). There was a strong positive relationship between plasma and uterine endometrial concentrations of both EPA (R(2)=0.86; P<0.0001) and total n-3 PUFA (R(2)=0.77; P<0.0001). IGF-1 concentrations increased on all diets and were greatest at the highest level of n-3 PUFA supplementation (P<0.05).
Effect of grazing and fat supplementation on production and reproduction of Holstein cows
  • Sl Boken
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