Follicular dynamics in anestrus Murrah buffaloes during cyclicity induction using ovsynch in different combinations
Abstract
Resumption of postpartum ovarian activity is essential for continued cycle of reproduction in order to achieve maximum life time production from milch animals .However , in buffaloes, the reproductive efficiency is mainly impaired by poor estrus expression, long intercalving intervals. Therefore, the present study was undertaken to study the effect of Ovsynch protocol in different combinations in postpartum anestrus Murrah buffaloes during low breeding season. Twenty four true anestrus buffaloes included in the experiment were randomly divided into four equal groups having six animals in each group. Group I was kept as control in which no treatment was administered. Group II received Ovsynch protocol alone where as Ovsynch protocol + CIDR and Ovsynch protocol + Hydroxyprogesterone were administered in group III and IV, respectively. The mean values of total number of follicles varied from 7.50±0.50 to 9.17±0.48, 8.50±0.50 to 12.80±1.56, 8.20±1.20 to 14.00±4.36 and 7.50±0.64 to 10.00±1.58 in groups I, II, III and IV, respectively on different days of examination. The mean values of diameter of ovulatory dominant follicles were 13.70±1.02, 13.03±0.89 and 12.67±0.82 mm in groups II, III and IV, respectively. There was no difference (P>0.05) among treated groups in diameter of ovulatory dominant follicles and second largest/subdominant follicles. The study revealed that the percentage of animals ovulated to both 1st and 2nd GnRH treatments were 83% (5/6), 16% (1/6) and 33% (2/6) in groups II, III and IV, respectively. The percentage of animals maintained CL on day 21 and 30 post A.I. were 66% (4/6), 33% (2/6), 33% (2/6) and 66% (4/6), 16% (1/6), 33% (2/6) in groups II, III and IV, respectively. In response to the Ovysnch treatment in different combinations 83% (5/6), 83% (5/6) and 66% (4/6) animals expressed estrus out of which 100% (5/5), 80% (4/5) and 100% (4/4) animals ovulated in groups II, III and IV, respectively. Out of animals that expressed estrus, 60% (3/5), 20% (1/5) and 0% (0/4) in groups II, III and IV, respectively were confirmed as pregnant using ultrasonography 30 days post A.I and subsequently at 60 days post A.I by rectal palpation. From the present investigation it can be concluded that Ovsynch alone is capable of inducing cyclicity and obtaining satisfactory conception rates in true postpartum anestrus buffaloes in summer season. However, it is suggested to extend the present investigation on large number of animals before final recommendation could be made for field application