Chiho Kawashima

Obihiro University of Agriculture and Veterinary Medicine, Obibiro, Hokkaidō, Japan

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Publications (34)54.74 Total impact

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    ABSTRACT: Recent studies have shown significant associations between prepartum energy status and postpartum fertility in dairy cows; therefore, the assessment of energy status by blood metabolites and metabolic hormones and suitable improvement of management during the prepartum period may enhance reproductive performance. Rumen fill score (RFS) is associated with feed intake; however, it is unknown whether RFS is also related to blood parameters. Therefore, this study investigated the relationship between RFS and energy status during the prepartum period, and their associations with conception at first artificial insemination (AI) after parturition. In 42 multiparous Holstein cows, RFS assessment and blood sampling were carried out twice a week during 3 weeks of the peripartum period. Ovarian cycles until AI were evaluated by measuring milk progesterone levels. Before calving, positive correlations were observed between RFS and total cholesterol, and RFS did not change in pregnant cows at first AI after parturition, whereas in non-pregnant cows, RFS decreased gradually as the calving day approached. After calving, non-pregnant cows showed lower energy status compared with pregnant cows, and some non-pregnant cows showed anovulation and cessation of estrous cycle. In conclusion, RFS during the close-up dry period is related to real-time energy status, and is associated with postpartum energy status and conception at first AI in dairy cows.
    No preview · Article · Jan 2016 · Animal Science Journal
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    ABSTRACT: This study aimed to investigate the effects of insulin resistance (IR) during the close-up dry period on the metabolic status and performance of dairy cows as well as to determine the effects on body weight (BW) and metabolic status of their calves. An insulin tolerance test (ITT) was conducted by administering 0.05 IU/kg BW of insulin to 34 multiparous Holstein cows at 3 weeks prepartum. Blood samples were collected at 0, 30, 45 and 60 min after insulin injection and cows were divided into two groups based on the time required for glucose to reach the minimum levels [non-IR (NIR), 45 min (n=28); IR, 60 min (n=6)]. Blood or milk sampling and body condition score (BCS) estimation were performed twice weekly during the experimental period. Blood samples from calves were collected immediately after birth. Cows with IR showed lower BCS (P<0.05) and serum urea nitrogen (P<0.05) and glucose concentration (P=0.05) before calving, and lower serum non-esterified fatty acid concentration (P<0.05) and milk yield (P<0.05) and earlier resumption of luteal activity (P<0.05) after calving; their calves showed lower BW (P<0.05) and plasma insulin-like growth factor-I concentration (P<0.001) and higher plasma insulin concentration (P<0.05). In conclusion, IR at 3 weeks prepartum in dairy cows is related to postpartum metabolic status and performance along with growth and metabolic status of their calves.
    Full-text · Article · Jan 2016 · Journal of Veterinary Medical Science
  • M Teramura · S Wynn · M Reshalaitihan · W Kyuno · T Sato · M Ohtani · C Kawashima · M Hanada
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    ABSTRACT: The incidence of hypocalcemia increases in high-parity dairy cows because resorption of bone Ca is delayed in these animals, and they appear to have a reduced ability to absorb Ca from the intestine during the early postpartum period. Difructose anhydride (DFA) III has been shown to promote the absorption of intestinal Ca via a paracellular pathway. However, past studies have not reported this effect in peripartum dairy cows. Therefore, we investigated the effect of DFA III supplementation on Ca metabolism during the peripartum period to determine whether DFA III promotes intestinal Ca absorption via this route. Seventy-four multiparous Holstein cows were separated into DFA and control groups based on their parity and body weight. The feed of the DFA group was supplemented with 40 g/d of DFA III from -14 to 6 d relative to calving. The control group did not receive DFA III. At calving (0 h relative to calving), serum Ca declined below 9 mg/dL in both groups. However, serum Ca concentrations were greater in the DFA group than in the control group at 6, 12, 24, and 48 h relative to calving, and the time required for serum Ca to recover to 9 mg/dL during the postpartum period was shorter in the high-parity cows in the DFA group than in those in the control group. Parathyroid hormone concentrations increased immediately after calving in both groups and were greater in the control group than in the DFA group at 12 and 24 h relative to calving. Serum 1,25-dihydroxyvitamin D concentrations increased at 0 and 12 h relative to calving in both groups and were higher in the control group than in the DFA group at 72 h relative to calving. Serum concentrations of the bone-resorption marker cross-linked N-telopeptide of type I collagen (NTX) were not different between the groups during peripartum period, and serum NTX in all cows was lower at 0, 6, 12, 24, 48, and 72 h relative to calving than at -21, 4, and 5 d relative to calving. Thus, DFA treatment induced faster recovery of serum Ca, although bone resorption was restrained. In conclusion, DFA III promotes intestinal passive Ca absorption via the paracellular pathway during the early postpartum period; this absorption is unaffected by aging.
    No preview · Article · Oct 2015 · Journal of Dairy Science
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    ABSTRACT: To determine the effects of puerperal metritis on the immune response, changes in the differential peripheral blood leukocyte counts were analyzed during the peripartum period in cows with or without metritis. Multiparous Holstein cows were examined for uterine health disorders and classified into two groups: healthy (n = 11) or metritis (n = 5) cows. The lymphocyte and monocyte counts and the proportion of CD8+ lymphocytes were higher in cows with metritis compared to healthy cows. Moreover, the effects of puerperal metritis on the lymphocyte counts and CD4+/CD8+ ratio persisted weeks after the uterine inflammation had self-resolved. Taken together, the findings of the present study indicate the possible long-term alterations of systemic immune responses in cows with puerperal uterine inflammation. © 2015 Japanese Society of Animal Science
    No preview · Article · Sep 2015 · Animal Science Journal
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    ABSTRACT: We investigated the effects of in vivo exposure to low zearalenone levels on the anti-Müllerian hormone endocrine levels and the reproductive performance of cattle. Urine and blood samples and reproductive records were collected from two Japanese Black breeding female cattle herds with dietary zearalenone contamination below the threshold levels (<1 ppm) at 30 days after calving. Urinary zearalenone, α-zearalenol and β-zearalenol concentrations were measured by chromatography-tandem mass spectrometry, and serum anti-Müllerian hormone concentrations were determined along with serum biochemical parameters. Urinary concentrations of α-zearalenol were significantly higher (p < 0.05) in cattle in Herd 1 than in cattle in Herd 2, reflecting the different amounts of zearalenone in the diet of the two herds. Although the number of 5-mm and 10-mm follicles of the herds and their fertility after artificial insemination were similar, the serum anti-Müllerian hormone concentrations in herds 1 and 2 were 438.9 ± 48.6 pg/ml and 618.9 ± 80.0 pg/ml, respectively, with a trend towards a significant difference (p = 0.053), which may indicate differences in the antral follicle populations between herds. Thus, zearalenone intake from dietary feed, even when below the threshold zearalenone contamination level permitted in Japan, may affect the ovarian antral follicle populations, but not the fertility, of post-partum cows.
    No preview · Article · Aug 2015 · Reproduction in Domestic Animals
  • M Teramura · T Nakai · M Itoh · T Sato · M Ohtani · C Kawashima · M Hanada
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    ABSTRACT: Difructose anhydride (DFA) III promotes the intestinal absorption of calcium via a paracellular pathway in rats. In dairy cows, DFA III reaches the duodenum without being degraded by ruminal bacteria and hence could be used to control hypocalcemia. The aims of the present study were to investigate the percentage of DFA III that appears in the duodenum of cows and to determine the effect of DFA III on calcium absorption from duodenal fluid. The first experiment was performed in 3 ruminally and duodenally cannulated dry Holstein cows in a 3 × 3 Latin square design. Each experimental period lasted 7 d. On the first day, the cows were ruminally fed one of the following treatments: 0 (DFA0), 50 (DFA50), or 100 (DFA100) g/d of DFA III, using cobalt-EDTA as a liquid phase marker. Difructose anhydride III was detected in duodenal fluid 1 h after feeding, and its concentration peaked 4 h after feeding, in a dose-dependent manner. The percentages of DFA III that appeared in the duodenum after the DFA50 and DFA100 treatments were 69.1 ± 7.0% and 67.9 ± 5.6%, respectively. The second experiment used the everted duodenal sacs of cattle (n = 7 in each group). Sacs were incubated in artificial mucosal fluid containing 1 mM DFA III or no DFA III (control) for 60 min with 100% O2 in a water bath at 37°C. After incubation, the calcium concentration of the artificial serosal fluid in the everted sacs was measured. Calcium absorption was higher in the DFA III-treated group than in the control group (803 ± 161 and 456 ± 74 nmol/cm of sac, respectively). The above results demonstrate that approximately 70% of administered DFA III reached the duodenum of cows intact. Moreover, similar to its effects on calcium absorption in rats, DFA III promoted calcium absorption via a paracellular pathway in the duodenum of cows. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Jan 2015 · Journal of Dairy Science
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    ABSTRACT: The present study aimed to assess the effect of polymorphisms in the tumor necrosis factor α (TNF-α) promoter (A/A, A/G and G/G) and exons (T/T, T/C and C/C) on immune function and reproductive performance in dairy cows. The occurrence of the first postpartum ovulation within 3 weeks in the cows with the TNF-α promoter A/G and G/G genotypes was higher than in the A/A group. Among the different TNF-α exon genotypes, the occurrence of early first postpartum ovulation was higher in the T/C and C/C genotype groups than in the T/T group. Single nucleotide polymorphisms (SNPs) in the TNF-α gene did not affect the rate of artificial insemination (AI) or duration from parturition to next conception (days open). The apoptosis rate of polymorphonuclear leukocytes (PMNs) did not differ among the TNF-α promoter genotypes, but the PMN transmigration rate was significantly higher for the A/A and A/G genotypes than for the G/G genotype. Interleukin 8 (IL-8) mRNA expression in PMNs and peripheral blood mononuclear cells (PBMCs) before culture was significantly higher for the A/A genotype compared with the G/G genotype. There were no significant differences between the genotypes in the mRNA expression of TNF-α, IL-6, IL-1β, and toll-like receptor 4 (TLR4) in PMNs and PBMCs before and 4 h after culture. IL-8 and IL-1β production by PBMCs cultured for 4 h was significantly higher for the animals with the A/A genotype than for those with the G/G genotype. On the other hand, no significant difference was observed in IL-8 and IL-1β production by PMNs among different TNF-α genotypes. Taken together, these results suggest that SNP in the TNF-α gene affects immune function and reproductive performance in dairy cows.
    Full-text · Article · Feb 2014 · Journal of Reproduction and Development
  • H Bollwein · C Kawashima · T Shimizu · A Miyamoto · M Kaske

    No preview · Article · Jan 2014
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    ABSTRACT: It is well known that the degree of negative energy balance in high-producing dairy cows is the major cause of delayed resumption of the ovarian cyclicity that closely relates to fertility. Recent evidence suggests that the energetic situation during early lactation critically affects nutrient partitioning, metabolism, and the reproductive axis, whereas the effect of energy status during the dry period is widely unknown. The aim of the present study was to investigate the effect of energy status throughout the entire dry period until early lactation on the onset of the ovarian cyclicity. Blood samples were taken in 23 cows from dry off at 8wk before expected parturition to 8wk postpartum for the analyses of metabolites and hormones, and milk samples were obtained 3 times weekly from d 7 of lactation onward to confirm luteal activity and pregnancy by milk progesterone analysis. Energy balance (EB) was measured weekly during the last 6wk of the dry period and every other week after parturition. Liver biopsies were obtained at 8wk before expected calving, within 1 d after calving, and at 4wk postpartum to measure the mRNA abundance of various gluconeogenic enzymes and metabolic hormone receptors. Cows showing luteal activity within 3wk postpartum were defined as ovulatory during the first follicular wave postpartum (OC), whereas cows without luteal activity within 3wk postpartum were defined as anovulatory (AC). Energy balance and, concomitantly, plasma concentrations of glucose, insulin, insulin-like growth factor-1, 3,5,3'-triiodothyronine, and thyroxine were higher in OC than in AC during the dry period. Plasma thyroxine concentrations and body condition score during the postpartum period were higher in OC than in AC. At the mRNA level (19 cows), hepatic insulin receptor decreased from dry off to early lactation, and mRNA of pyruvate carboxylase was highest at parturition and decreased in early lactation in AC only, whereas both parameters remained unchanged in OC. The mRNA abundance of phosphoenolpyruvate carboxykinase-mitochondrial increased from dry off to parturition in both groups, remained high in OC, and decreased again in early lactation in AC. However, none of the investigated gene transcripts differed between OC and AC cows. Thus, ovarian function postpartum appears to be crucially influenced by the energy status during the dry period, which is reflected by timely changes in hepatic mRNA abundance of only a few key metabolic factors in the liver.
    No preview · Article · Aug 2012 · Journal of Dairy Science
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    ABSTRACT: During recent decades, milk production per cow has increased drastically due to improved management, nutrition, and genetic selection; however, the reproductive performance of high-producing dairy cows has been declining. One of the factors responsible for this low reproductive performance is negative energy balance (NEB). NEB affects the onset of first ovulation in early postpartum cows. It is generally accepted that early first ovulation positively relates to the resumption of normal ovarian function, first service, and conception rate in dairy cows. Hence, delayed first ovulation has a negative impact on subsequent fertility. The metabolic condition of cows in NEB shifts to catabolic metabolism, which in turn causes increased plasma growth hormone and non-esterified fatty acid concentrations and decreased plasma insulin-like growth factor-1, insulin, and glucose concentrations. On the other hand, plasma β-carotene concentrations decrease throughout the dry period and reach their nadir in about the first week postpartum, and this change reflects energy balance during the peripartum period. β-Carotene plays a role independently of vitamin A in the reproductive performance of dairy cows, and the positive relationship between supplemental β-carotene and reproductive function has been demonstrated in many studies during the past decades. However, β-carotene content in corn silage, which is a popular main feed in high-producing dairy cows, is very low. This review describes nutritional factors related to ovulation during the first follicular wave postpartum in dairy cows.
    No preview · Article · Feb 2012 · Journal of Reproduction and Development
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    Katsuya Kida · Chiho Kawashima · Akio Miyamoto · Hassan Hakimi

    Full-text · Article · Jan 2012
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    ABSTRACT: In peripartum dairy cows, insulin resistance (IR) increases to adjust the direction of energy to lactation after calving. To investigate the effect of prepartum IR on postpartum reproductive performance, the insulin tolerance test (ITT) was applied to 15 cows at 3 weeks (Pre21) and 10 days (Pre10) before the predicted calving date. Blood glucose area under the curve (AUC(glu)) within 120 min after administration of 0.05 IU/kg-BW insulin was calculated. The occurrence of first ovulation, days to first artificial insemination (AI) and first AI conception rate were recorded. Nutritional status postpartum was evaluated by blood chemical analysis. Based on AUC(glu) changes from Pre21 to Pre10, cows were classified into either the AUC-up group (AUC(glu) increase, n=5) or the AUC-down group (AUC(glu) decrease, n=10). There was no difference in the decrease in blood glucose at 30 min after insulin injection between groups, although glucose recovery from 30 to 60 min during the ITT was slow at Pre10 in the AUC-up group. The AUC-up group had a higher number of days to first AI and high glucose, total protein, globulin, γ-glutamyltransferase, triacylglycerol levels and a low albumin-globulin ratio at the 14th day postpartum. The present study infers that prepartum slow glucose recovery rather than insulin sensitivity might increase the potential for subclinical health problems postpartum and thus suppress reproductive performance. During the prepartum transition period, glucose dynamics in the ITT can be considered as a new indicator for the postpartum metabolic status and reproductive performance of dairy cows.
    No preview · Article · Dec 2011 · Journal of Veterinary Medical Science
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    ABSTRACT: In cows, interferon-tau (IFNT) regulates maternal recognition around days 15-19 after artificial insemination (AI). The present study hypothesized that if key target genes of IFNT are clearly upregulated in earlier stages of pregnancy, these genes could be use as indices of future pregnancy in cows. Therefore, we determined the expression of these genes in peripheral blood mononuclear leukocytes (PBMCs) and polymorphonuclear granulocytes (PMNs) during the maternal recognition period (MRP). Twenty multiparous Holstein cows were subjected to AI on day 0 and categorized into the following groups: pregnancy (Preg, n = 9), embryonic death (ED, n = 5) and non-pregnancy (NP, n = 6). Progesterone levels in the Preg group were higher than those in the NP group on days 12-21. ISG15 and OAS-1 (IFN-stimulated genes: ISGs) mRNA in PBMCs on day 8 was higher in the Preg group than in the NP group, and these mRNAs in PMNs was higher in the Preg group on day 5 than in the NP and ED groups. Interleukin-10 (IL-10, Th2 cytokine) mRNA expression increased on day 8 in the PBMCs of pregnant cows. Tumor necrosis factor α (TNFα, Th1 cytokine) mRNA expression was stable in all groups. In an in vitro cell culture experiment, IFNT stimulated mRNA expression of ISGs in both PBMCs and PMNs. IFNT stimulated IL-10 mRNA expression in PBMCs, whereas IFNT increased TNFα mRNA levels in PBMCs in vitro. The results suggest that ISGs and IL-10 could be responsive to IFNT before the MRP in peripheral blood immune cells and may be useful target genes for reliable indices of pregnancy before the MRP.
    No preview · Article · Nov 2011 · Journal of Reproduction and Development
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    ABSTRACT: Many metabolic hormones, growth hormone (GH), insulin-like growth factor-I (IGF-I) and insulin affect ovarian functions. However, whether ovarian steroid hormones affect metabolic hormones in cattle remains unknown. This study aimed to determine the effect of sex steroids on the plasma profiles of GH, IGF-I and insulin and their receptors in the liver and adipose tissues of dairy cows. Ovariectomized cows (n = 14) were randomly divided into four groups: control group (n = 3) was treated with saline on Day 0; oestradiol (E2) group (n = 3), with saline and 1 mg oestradiol benzoate (EB) on Day 0 and 5, respectively; progesterone (P4) group (n = 4) with two CIDRs (Pfizer Inc., Tokyo, Japan) from Day 0; and E2 + P4 group (n = 4) with two CIDRs on Day 0 that were removed on Day 6 and were immediately injected with 1 mg EB. The animals were euthanized after the experiment, and liver and adipose tissues samples were quantitatively analysed using real-time PCR for the expression of mRNA for the GH (GHR), IGF-I (IGFR-I) and insulin (IR) receptor mRNAs. Oestradiol benzoate significantly increased the number of peaks (p < 0.05), pulse amplitude (p < 0.05) and area under the curve (AUC; p < 0.01) for plasma GH; moreover, it increased plasma IGF-I concentration (p < 0.05), but it had no effect on the plasma insulin profile. P4 significantly decreased the AUC (p < 0.01), compared with the control group, whereas it did not affect the number of peaks and the amplitude of GH pulses. P4 + E2 did not affect the GH pulse profile. E2 increased the mRNA expression of GHR, IGFR-I and IR in the liver (p < 0.05), whereas both P4 and E2 + P4 did not change their expressions. Our results provide evidence that the metabolic and reproductive endocrine axes may regulate each other to ensure optimal reproductive and metabolic function.
    No preview · Article · Feb 2011 · Reproduction in Domestic Animals
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    ABSTRACT: The decrease in fertility and conception rates of high-producing dairy cows is one of the major negative impacts for today's producers. The recovery of ovarian activity postpartum is affected by the status of immunity, metabolism and reproduction and plays a critical role in subsequent fertility after parturition in the cow. In the present study we investigated the relationships between polymorphisms in genes relating to the above functions and the first postpartum ovulation as a marker of the recovery of ovarian function in the cow. In immune function related-factors, the occurrence of first postpartum ovulation within 3 weeks in the C/C genotypes of tumor necrosis factor α (TNFα) exon (55.4%) and the A/G genotypes of TNFα promoter (55.4%) was significantly higher than that in T/T genotypes of TNFα exon (14.3%) and A/A genotypes of TNFα promoter (14.3%). Moreover, anovulatory cows with the T/T genotype of TNFα exon and the A/A genotype of TNFα promoter tended to have a prolonged days open compared with those of the other genotypes of TNFα polymorphisms. In metabolic function-related factors, ovulatory and anovulatory cows had a different distribution for alleles of the growth hormone receptor, but there were no significant differences in genotype and allele frequency of insulin-like growth factor-I polymorphism. No significant relationships were found between ovarian function after parturition and polymorphisms for reproduction-related genes. In conclusion, polymorphisms of TNFα gene both in exon and promoter regions have a strong association with the early first ovulation within 3 weeks after parturition in the high-producing dairy cow. Taken together, polymorphisms of TNFα gene could be strongly related to early first ovulation after parturition, thus being an effective tool of selection for improving reproductive performance in the high-producing dairy cow.
    Full-text · Article · Nov 2010 · Journal of Reproduction and Development
  • C Kawashima · S Nagashima · K Sawada · F J Schweigert · A Miyamoto · K Kida
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    ABSTRACT: The aim of this study was to examine the effect of β-carotene supply during the close-up dry period on the onset of first postpartum luteal activity in dairy cows. Twelve cows were supplied with 2000 mg of β-carotene (20 g Rovimix(®) β-Carotene containing 10% β-carotene; DSM Nutrition Japan K.K., Tokyo, Japan) by oral administration daily from day 21 before expected calving date to parturition. Fourteen cows (control) did not receive β-carotene supplementation. Blood samples were obtained on days 21, 14 and 7 before expected calving date and on days 1, 7, 14, 21 postpartum. When the plasma progesterone concentration exceeded 1 ng/ml by day 21 postpartum, luteal activity was assumed to have been initiated. The result showed that serum β-carotene concentrations in the β-carotene cows were higher than in the control cows during the experimental period (p < 0.01). The number of cows with the onset of luteal activity by day 21 postpartum was 9/12 in the β-carotene cows and 4/14 in the control cows (p < 0.05). Retinol, certain metabolic parameters and metabolic hormones concentrations did not differ between β-carotene and control cows. In addition, serum retinol concentration in β-carotene cows without luteal activity was lower than in β-carotene cows with luteal activity (p < 0.05), and serum gamma-glutamyl transpeptidase concentration in β-carotene cows with luteal activity (p < 0.05) and control cows without luteal activity (p < 0.01) was higher than in control cows with luteal activity. In conclusion, β-carotene supply during the close-up dry period may support the onset of luteal activity during early lactation in dairy cows.
    No preview · Article · Dec 2009 · Reproduction in Domestic Animals
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    ABSTRACT: The sex ratio of mammals has previously been shown to be affected by maternal stress. In our previous study, the proportion of female embryos collected from superovulated and artificially inseminated Holstein heifers that were frequently placed in stanchions and subjected to transrectal examinations of the ovaries during the follicular phase tended to be higher than the expected 50%. The goal of the present study was to test the validity of this observation using a greater number of heifers. Superovulated heifers were artificially inseminated at 56 and 72 h after PGF(2alpha) treatment using a single batch of frozen semen. Frequent capture (FC), transrectal examination and/or blood sampling were performed at 4-h intervals from 36 to 76 h after PGF(2alpha) treatment (n=13). Nine heifers were used as the Control (non-treatment). Seven-day-embryos were recovered by uterine flushing. Male and female embryos were separated using the loop-mediated isothermal amplification procedure. The proportion of female transferable embryos in the FC group (67.8%, 78/115) was significantly higher than that in the Control group (51.2%, 43/84, P<0.05). The peak concentration of plasma cortisol during the follicular phase following superovulatory treatment was 20.6 ng/ml in the FC group. These results suggest that subjecting heifers to stress during the follicular phase following superovulatory treatment may increase the female sex ratio of embryos.
    No preview · Article · Jun 2009 · Journal of Reproduction and Development
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    ABSTRACT: This study was undertaken to produce trophoblastic vesicles (TVs) by using blastocysts of in vitro origin and to estimate the effect on the interestrous interval after transfer of 4 TVs into the uteri of heifers on Day 7. Morphological examination under a stereoscopic microscope revealed that the total formation rate of TVs prepared from IVP expanded blastocysts was 80.5% and that there was no difference in the formation rates of TVs derived from blastocysts between Day 7 (83.5%) and Day 8 (78.5%). After intrauterine transfer of TVs, observation of the corpus luteum (CL) by transrectal ultrasonography together with measurement of the plasma progesterone concentration confirmed that 2 of 4 recipients (50%) had a longer interestrous interval, 33.5 and 35.0 days, while the other 2 recipients had normal cycles, 20.0 and 24.5 days. In the control group transferred D-PBS, all 4 heifers had a normal cycles, 24.0-24.5 days. Consequently, the average number of days after intrauterine transfer of TVs compared with the 2 consecutive cycles just before the treatment was longer than in the controls (6.1 +/- 2.4 days vs. -0.8 +/- 1.1 days, P<0.05). These results indicate that preparation of TVs from blastocysts of in vitro origin is a useable method and that TVs from blastocysts may have the capacity to maintain CL function after intrauterine transfer.
    No preview · Article · May 2009 · Journal of Reproduction and Development
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    ABSTRACT: Insulin and growth hormone (GH) play critical roles in the process of follicular development and maturation. However, the involvement of insulin receptor (IR) and GH receptor (GHR) during follicular development is not well understood. The aim of this study was to investigate the expression of IR and GHR mRNAs in the granulosa cells (GCs) and theca tissues (TCs) of the follicle at different developmental stages (preovulatory dominant follicles, POFs; estrogen-active dominant follicles, EADs; estrogen-inactive dominant follicles, EIDs; and small follicles, SFs), and second, to examine the effects of follicle-stimulating hormone (FSH) and estradiol (E2) on the expression of IR and GHR genes in cultured bovine GCs. Although the concentration of insulin in follicular fluid (FF) was constant at all developmental stages, the GH concentration in FF was significantly increased in the EAD and POF compared with the EID. IR mRNA in GCs and TCs was significantly increased in the POF compared with other follicles. Regarding GHR expression, significant increases of mRNA expression were observed in GCs of EAD compared to those of SF, EID and POF. GHR mRNA in TCs was significantly decreased in the SF compared with other follicles. In cultured GCs, FSH, but not E2, stimulated the expression of IR and GHR genes. Our results suggest that the increase in the expression of GHR may be a turning point for follicles to enter the ovulatory phase during final follicular development and that the insulin system may support the maturation of preovulatory follicles.
    No preview · Article · Jul 2008 · Animal Reproduction Science
  • C Kawashima · K Kida · F.J. Schweigert · A Miyamoto
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    ABSTRACT: Beta-carotene functions independently of vitamin A in the reproductive performance of dairy cows. The concentrations of beta-carotene in plasma decrease during the dry period, and reach a nadir in about the first week postpartum. This coincides with a negative energy balance, which affects the onset of the first ovulation in early postpartum cows. Thus, we hypothesised that plasma beta-carotene concentrations during the peripartum period may affect ovulation in the first follicular wave postpartum in dairy cows. The aim of the present study was to investigate changes in the profiles of plasma beta-carotene concentrations during the peripartum period in ovulatory and anovulatory cows during the first follicular wave postpartum. We used 22 multiparous Holstein cows, which were fed a total mixed ration consisting of grass, corn silage and concentrate, and collected blood samples for beta-carotene and progesterone analysis from week 3 prepartum to week 3 postpartum when the period of day 0-6 after parturition was regarded as the parturient week (week 0). The first ovulation was confirmed using the profile of plasma progesterone concentrations and colour Doppler ultrasound. Thirteen cows ovulated during the first postpartum follicular wave. Parity, the dry-off period, calving interval, mastitis episodes, and actual 305 days' milk yield during the previous lactation, and milk composition in the last month during the previous lactation in this study did not differ between ovulatory and anovulatory cows. Differences in the plasma beta-carotene profile were observed between ovulatory and anovulatory cows. Plasma beta-carotene concentrations at week 3 prepartum were greater in ovulatory cows (2.97+/-0.24 mg/L) than in anovulatory cows (1.53+/-0.14 mg/L; P<0.001), after that its concentrations in ovulatory cows decreased and reached the lowest level at week 1 postpartum, although its concentrations in anovulatory cows remained unchanged. No differences in plasma beta-carotene concentrations between the two groups were observed postpartum. The present study indicates for the first time that the lower beta-carotene concentrations in plasma during the prepartum period is associated with anovulation during the first follicular wave postpartum.
    No preview · Article · Mar 2008 · Animal reproduction science