Abstract

This investigation was aimed to evaluate the fertility response in 55 postpartum (gt;90 days) anoestrus rural buffaloes treated with three standard hormonal protocols (CIDR, Ovsynch and Crestar, n=15 each), keeping a group of untreated control (n=10), and the findings were compared with a group of normal cyclic control buffaloes (n=10). All the 15 (100 %) buffaloes in each group under CIDR, Ovsynch and Crestar protocols exhibited induced oestrus with prominent, moderate or weak oestrus signs within mean intervals of 65.00#xB1;1.55, 69.46#xB1;1.04 and 46.00#xB1;1.37 hrs, respectively, from PGF2#x3B1; injection. The conception rates obtained at induced oestrus in buffaloes under CIDR, Ovsynch and Crestar protocols were 46.67, 53.33 and 33.33 per cent, respectively. The corresponding overall conception rates of three cycles were 66.67, 73.33 and 60.00 per cent. These were achieved with the mean intervals from PGF2#x3B1; injection of 11.40 #xB1; 4.65, 12.70 #xB1; 5.13 and 10.88 #xB1; 3.84 days among treated conceived buffaloes in three groups, respectively. In untreated anoestrus control (n=10), only 2 buffaloes exhibited spontaneous oestrus within 90 days of follow up and one conceived giving first service and overall pregnancy rates of 50.00 and 10.00 per cent, respectively. In normal cyclic control (n=10), the conception rates at first and overall of 3 cycles were 40.00 and 70.00 per cent, respectively, and the service period was of 105.67 #xB1; 7.44 days among conceived ones. The overall mean plasma progesterone concentrations in true anoestrus buffaloes on day 0, 7, 9 (AI) of treatment and on day 21 post-AI were 1.13 #xB1; 0.66, 4.97 #xB1; 1.68, 0.73 #xB1; 0.67 and 3.47 #xB1; 1.89 ng/ml, respectively, in CIDR protocol; 1.09 #xB1; 0.15, 3.75 #xB1; 0.47, 0.58 #xB1; 0.10 and 4.06 #xB1; 0.47 ng/ml in Ovsynch and 1.12 #xB1; 0.36, 1.28 #xB1; 0.15, 0.66 #xB1; 0.10 and 2.44 #xB1; 0.44 ng/ml in Crestar protocol, respectively. The values on day 7 and 21 were significantly (Plt;0.01) higher than other two periods in all three groups. The mean