Effect of prostaglandin on estrus response and conception rate in lactating ongole cows

摘要

Aim: The present research work was carried to study the estrus response and conception rate in lactating Ongole cows consequence to double injection of prostaglandin. Materials and Methods: Estrus synchronization was performed by double injection of PGF2α (Lutalyse, 5ml/cow) in purposively selected 22 lactating Ongole cows. The 1st injection was administered on 60 days post partum (day 0) followed by 2nd injection on 72 days postpartum (day 12) and then insemination was carried out at observed estrus. Results: The ovarian response by ultrasound scanning revealed a dominant follicle of 10.00 + 0.78 mm 3-4 days after the PGF2α administration. Out of 22 cows treated with double injections of prostaglandins 18 cows exhibited estrus within 68.66 + 10.24 hrs. The duration of estrus and mean estrous cycle length recorded as 14.20 + 2.56 hrs and 21.50 + 0.21 days, respectively. The estrous cycle was observed in 79.45 % cows. The remaining cows showed 11-17 (5.48%), 26-36 (9.59%) and 37- 60 (5.48 %) days of estrous cycle length. The conception rate of observed to be 67.00 + 0.26 %. The mean calving to service period found to be 81.18 + 1.62 days in lactating multiparous Ongole cows. Conclusion: It may be concluded that double injection of Prostaglandin has reduced the calving to service period which would even truly reduce calving interval in lactating Ongole cows.