Study on different estrus induction protocols with respect to fertility and plasma progesterone profile in anoestrus buffaloes

Abstract

This study was carried out to evaluate the clinical response and monitor the peripheral plasma progesterone profile in 46 postpartum anoestrus buffaloes (>90 days) treated with different standard hormonal protocols (TriU-B/PRID, Ovsynch and Heatsynch, n=12 each), keeping untreated anoestrus control (n=10) and normal cyclic control (n=10) groups. Under these protocols estrus induction response was 83.33, 83.33 and 91.66 per cent within mean intervals of 69.30±0.80, 70.60±1.30 and 69.20±1.49 h, respectively from PG injection with prominent to moderate estrus signs. The conception rates (CRs) obtained at induced estrus in buffaloes under TriU-B, Ovsynch and Heatsynch protocols were 25.00, 33.33 and 25.00 per cent, respectively. The corresponding overall CRs of three cycles were 50.00, 58.33 and 50.00 per cent. Moreover, by 60 days of post-induction follow up among treated non-conceived buffaloes under TriU-B, Ovsynch and Heatsynch protocols 4, 2, 2 remained cyclic, while 2, 3, 4 buffaloes turned out to be anoestrus. In untreated anoestrus control group, out of 10 buffaloes only 2 buffaloes (20 %) expressed spontaneous estrus and conceived giving overall CR of 20.00 per cent. In normal cyclic control group (n=10) the CRs at first and overall of 3 cycles were 30.00 and 50.00 per cent, respectively. The overall mean plasma progesterone concentrations (ng/ml) found in true anoestrus buffaloes on day 0, 7, 9/10 (AI) of treatment and on day 21 post-AI were 0.44±0.13, 3.07±0.56, 0.20±0.02 and 3.26±1.07 under TriU-B protocol; 0.49±0.13, 3.03±1.02, 0.51± 0.30 and 3.49±1.24 under Ovsynch protocol and 0.39±0.08, 2.08±0.32, 0.46±0.12 and 2.94±1.14 under Heatsynch protocol. The values on day 7 of treatment and day 21 post-AI were significantly (P<0.01) higher than other two periods (day 0 - initiation of treatment, and day of estrus/FTAI) in all three groups. The mean plasma progesterone concentrations (ng/ml) were significantly (P<0.01) higher in conceived than non-conceived groups on day 21 post-AI under TriU-B (5.90±0.83 vs. 0.61±0.10) Ovsynch (6.60±0.84 vs. 0.38±0.14) and Heatsynch (6.60±1.11 vs. 0.74±0.21) protocol, and even in normal cyclic control buffaloes (4.39±0.15 vs. 1.52±0.43). Thus, all the three hormonal protocols used in anoestrus buffaloes resulted into more than 83 per cent estrus induction and good conception rates (50-58%) particularly with Ovsynch protocol suggestive of better scope for their use under field conditions.