Estrus Induction Response Vis-a-Vis Serum Progesterone and estradiol 17-β Profile in Postpartum Subestrus Surti Buffaloes Primed with Heatsynch Alone and Heatsynch plus PRID Protocol

This study was conducted on 18 subestrus Surti buffaloes at University farm to estimate steroidhormone values before, during and after use of Heatsynch (T1) and Heatsynch+PRID (T2) protocols.In the Heatsynch protocol (n=6), buffaloes were administered intramuscularly with inj. Busereline- GnRH analogue on day 0, inj. Cloprostenol sodium-PGF2α analogue on day 7 and inj. EstradiolBenzoate (EB-) on day 8. In the Heatsynch+PRID protocol (n=6), PRID was inserted intra-vaginallyand kept in situ for 7 days with inj. Buserelineon day 0. The PRID was removed on day 7 togetherwith inj. of Cloprostenol and inj. EB was administered on day 8. FTAI was done twice on day 10in both the groups. No treatment was given to control (n=6) group (T3). The estrus response was100% in all three groups, but the conception rate at first cycle/service was 50.00, 66.66 and 33.33%,respectively, in three groups. The mean plasma progesterone concentrations were significantly loweron day of estrus (0.26±0.05, 0.63±0.07and 0.58±0.08 ng/ml in T1, T2 and T3 respectively) ascompared to the corresponding values on day 0, 4, 8 of treatment and 18 post-AI in all the threegroups.The mean values of estradiol-17β markedly increased (p less than 0.01) on the day of estrus intreatment groups T1 and T2 (43.45±1.42 pg/ml and 42.86±1.53 pg/ml) than control group T3 (35.74±0.63pg/ml) and thereafter markedly decreased at 18th day post-AI in all the groups (17.93±4.49;16.34±2.14; 25.52±3.10 pg/ml) with non-significant difference.