The aim was to establish the capacity of buffalo heifers to adapt their metabolic requirements to a low energy diet. Murrah buffalo (Bubalus bubalis) heifers undergoing regular estrous cycles were randomly assigned by age, live weight (LW) and body condition score (BCS) to a high energy group (HE, 5.8 milk forage units (MFU)/day, n=6) or low energy group (LE, 3.6 MFU/day, n=6). Circulating concentrations of metabolic substrates, metabolic hormones and reproductive hormones were determined weekly for 19 weeks. Ovarian follicular characteristics and oocyte parameters were also ascertained weekly. Heifers fed the LE diet had a better dry matter conversion than heifers fed the HE diet and the calculated daily energy provision was negative for heifers fed the LE diet (-0.248 MFU) and positive for heifers fed the HE diet (5.4 MFU). Heifers fed the HE diet had an increase in 50 kg LW over the duration of the study whereas LW remained constant for heifers fed the LE diet. The BCS of heifers fed the HE diet (4.2) was greater (P<0.05) than the BCS for heifers fed the LE diet (3.4). Heifers fed the HE diet had greater (P<0.05) circulating concentrations of metabolic substrates (glucose, total cholesterol and HDL cholesterol) and metabolic hormones (insulin, glucagon, leptin and T3) compared with heifers fed the LE diet. There were no significant differences in circulating reproductive hormones between the two groups of heifers. Ovarian follicular characteristics were similar for the two groups of heifers while heifers fed the LE diet tended to have oocytes of reduced quality compared with heifers fed the HE diet. The most notable finding was that heifers fed the LE diet had a negative calculated daily energy provision but were able to maintain LW and reproductive activity. It was concluded that buffalo heifers may potentially have the capacity to undergo metabolic adjustment and reduce their energy requirements when dietary energy is limiting. This adaptive capacity would explain why buffaloes remain productive in environments that are limiting to other ruminants.
"Several impacts of nutrition and climate on reproductive parameters were reported (Santos et al. 2008; Campanile et al. 2010a,b). However, most of these studies have been performed in countries with a temperate climate (Rensis and Scaramuzzi 2003; Hansen 2004). "
[Show abstract][Hide abstract] ABSTRACT: This study was performed to evaluate plasma concentrations of anti-Mullerian hormone (AMH) and the ovarian antral follicle population (AFP) in different genetic groups. Cyclic heifers (13 Bubalus bubalis [Murrah]; 15 Bos taurus [Holstein] and 10 Bos indicus [Gyr]) were maintained under the same management and were synchronized with two doses of 150 μg IM d-cloprostenol administered 14 days apart. After the second d-cloprostenol treatment, heifers had their ovaries scanned daily by ultrasound to define the day of ovulation. On the same day, the AFP was determined and a plasma sample was collected to measure AMH. Murrah heifers had less AFP (25.6 ± 2.1 follicles; p = 0.01) and plasma AMH concentration (0.18 ± 0.03 ng/ml; p < 0.001) than Gyr (60.0 ± 12.2 follicles and 0.60 ± 0.12 ng/ml of AMH); however, data were similar when compared to Holstein (35.9 ± 6.8 follicles and 0.24 ± 0.06 ng/ml of AMH) heifers. Regardless of genetic background, there was a positive relationship between the AFP and plasmatic AMH concentration (Murrah [r = 0.62; p < 0.01], Holstein [r = 0.66; p < 0.001] and Gyr [r = 0.88; p < 0.001]). Also, when heifers were classified according to high- or low-AMH concentration based on the average within each genetic group, high-AMH heifers had greater (p < 0.0001) AFP than low-AMH heifers. In conclusion, both Murrah and Holstein heifers presented lower plasma AMH concentration and AFP when compared to Gyr.
"However, in this study NEFA levels, in both groups, fluctuated within the physiological range for this species (Borghese et al., 2010; Campanile et al., 2010) and no significant changes were observed during the experimental period. Glucose levels recorded in Experiment I were lower than those obtained in Experiment II. "
[Show abstract][Hide abstract] ABSTRACT: In order to evaluate the influence of rearing system (free-ranging (FR) v. confinement (C)) on buffalo heifer efficiency to reach age of puberty and on behavioural and immune functions, two experiments were conducted from September 2010 to October 2011. In Experiment I, 32 subjects aged 8 to 9 months at the start of experiment were used. A total of 16 animals (group C) were group housed in an indoor slatted floor pen (4 m2/animal) with an outdoor paddock (4 m2/animal); 16 others grazed on a Mediterranean natural pasture of 40 ha (group FR). Behavioural data were collected and organic matter digestibility, blood metabolites and progesterone were determined. At the end of the experiment, a novel object test and a skin test were conducted, and the avoidance distance (AD) at the manger was measured. Free-ranging animals were able to express natural behaviours such as wallowing and grazing. C animals devoted more time to the novel object than FR animals, whereas AD at manger was lower in group FR than in group C (P<0.01). Cellular immune response was higher in FR heifers than in C animals (P<0.01). FR animals also showed a higher digestibility of organic matter (P<0.01). Heifers from group FR had higher plasma concentrations of non-esterified fatty acids (P<0.001) and lower concentrations of glucose than heifers from group C (P<0.001). C animals showed higher daily weight gains (P<0.01) and weight at the puberty (P<0.05), but there were no differences in terms of age of puberty between the two groups. The intakes of dry matter (DM), CP and energy to reach the age of puberty were similar in both groups. In order to verify whether the results obtained in Experiment I could be replicated in different rearing conditions (reduced pasture availability, different location and altitude), a second experiment was conducted on 26 animals, where only onset of age of puberty and metabolic profile were monitored. In Experiment II, 13 heifers grazed on a natural pasture of 5 ha, other 13 received the same space as indicated for Experiment I. Results from Experiment II generally confirmed those of Experiment I. Only the intakes of DM and energy to reach the age of puberty were higher in group C than in FR (P<0.001). A lower competition with human nutrition, reproductive performances similar to those shown by confined animals and the indications given by immune and behavioural variables, suggest that a free-range-based system may be conveniently used for buffalo heifer farming purposes.
"Whereas body condition was shown to alter the serum thyroid hormones in ruminants, which mediates the ovarian effects of nutrition, females receiving high energy diets depicted increased levels of glucose, total cholesterol , insulin, leptin and T3 and tended to have oocytes of increased quality (Campanile et al., 2010). The results of these studies demonstrate that TH plays a positive and permissive action upon reproductive function. "
[Show abstract][Hide abstract] ABSTRACT: Abstract
The effect of betacarotene (BC) supplementation on serum triiodothyronine (T3) levels over time in prepubertal goats was evaluated. Goats (n = 17; 3 months old; 7/8 Saanen-Alpine; 26° NL) were randomly assigned to one of the following two groups: 1) the betacarotene group, supplemented daily with 50 mg of BC (n = 9; live weight [LW]: 17.3 ± 1.0 kg; body condition score [BCS]: 3.34 ± 0.12), or 2) the control group (CC; n = 8; LW:16.1 ± 1.0 kg; BCS = 3.17 ± 0.12). The initial mean LW (16.7 ± 1.0 kg) and BCS (3.31 ± 0.12) were similar (p > 0.05) in both groups. Whereas BC supplementation did not affect the onset of puberty (215.7 vs. 226.7 ± 6.6 days; p > 0.05) for the BC and CC, respectively, increases in serum T3 during the second half of the experiment were observed in the BC supplementation group (p < 0.05). As the LW and serum T3 levels increased, the natural photoperiod decreased, revealing a negative correlation (p < 0.05) between the variables; the observed values were r = - 0.94 for LW and photoperiod and r = - 0.41 for T3 and photoperiod. Long-term BC supplementation was not associated with a precocious onset or an increased percentage of goats reaching puberty. Long-term BC supplementation positively affected the release pattern of triiodothyronine over time, suggesting a potential role of BC as a thyroid-activating molecule; these results might possess clinical significance.
Additional keywords: Goats, betacarotene, puberty, progesterone, triiodothyronine.
Small Ruminant Research 02/2014; 116:176-182. DOI:10.1016/j.smallrumres.2013.10.017 · 1.13 Impact Factor
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