Influence of controlled breeding techniques on fertility and plasma progesterone, protein and cholesterol profile in true anestrus and repeat breeding buffaloes

Aim: The aim was to evaluate the estrus response, conception rate and plasma profile of progesterone, protein and cholesterol following use of different hormonal protocols in anestrus and repeat breeding buffaloes. Materials and Methods: This study was carried out on 20 true anestrus, 20 repeat breeders, and 10 normal cyclic buffaloes. Ten anestrus buffaloes each were treated with standard controlled internal drug releasing (CIDR) i/vg device and Ovsynch (GPG) protocols with fix timed artificial insemination (FTAI), and blood samples were obtained on day 0, 7, 9/10 (AI) of treatment and day 21 post-AI. Ten repeat breeding buffaloes with mature mid-cycle palpable corpus luteum (CL) were treated with i/m injection of 25 mg prostaglandin F2α (PGF2α) with FTAI twice at 72 and 96 h later, whereas other ten repeat breeding buffaloes in standing estrus were inseminated with simultaneous i/m injection of buserelin acetate-gonadotropinreleasing hormone (GnRH) 20 μg. 10 buffaloes exhibiting first estrus within 90 days postpartum and inseminated without any treatment served as normal cyclic control. Blood samples were obtained on day of PG injection, day of AI and day 21 post-AI for estimation of plasma progesterone, protein, and cholesterol. Results: CIDR and Ovsynch protocols resulted in 100 and 80% induction of estrus with conception rates of 40 and 30% at induced estrus, respectively, in anestrus buffaloes. Mid-cycle PGF2α treatment resulted in 90% estrus induction and 40% conception rate at induced estrus, while Buserelin acetate-GnRH 20 μg injection at AI resulted in 30% conception rate in repeat breeders. In normal cyclic control group also, the first service conception rate was 30%. The mean plasma progesterone concentrations on day 0, 7, 9/10 (AI) of treatment and on day 21 post-AI were found to be significantly (p<0.05) different in both CIDR and Ovsynch protocols, being higher on day 7 (day of PG injection) and on day 21 post-AI than on day 0 and 9/10 (FTAI), which were near basal levels. The mean plasma progesterone level was significantly (p<0.01) higher on the day of initiation of mid-cycle PGF2α treatment (3.81±0.67 ng/ml) in a repeat breeding buffaloes suggesting luteal phase. The mean plasma P4 levels on day 21 post-AI were significantly (p<0.01) higher than on the day of estrus in both repeat breeders and in normal cyclic controls. The plasma P4 value on day 21 post-AI was significantly (p<0.01) higher in conceived than non-conceived buffaloes in all five groups. The mean plasma total cholesterol and total protein concentrations in anestrus and repeat breeding buffaloes under different treatments did not vary significantly between sampling days. However the cholesterol content was significantly (p<0.05) lower (79.96±2.17 vs. 92.27±6.04 mg/dl) and protein higher (8.14±0.73 vs. 7.69±0.59 g/dl) in conceived than non-conceived animals. In both anestrus and repeat breeding buffaloes, the values of cholesterol and protein were significantly lower than in normal cyclic control group (138.04±11.98 mg/dl and 7.82±0.11 g/dl, respectively). Conclusion: The results showed that CIDR was better than Ovsynch protocol in inducing fertile estrus in anestrus buffaloes, while mid-cycle PG treatment was superior over AI + GnRH in repeat breeders, and all four treatment protocols significantly influenced plasma P4 profile, but not the protein or cholesterol.