Kumar R, *Phogat JB, Mann JS, Singh U, Sharma AK
The present study was conducted with 25 lactational anestrus mares during late breeding season (July/August) dividing randomly in Treatment (n=15) and Control Groups (n=10). In Treatment Group, a progesterone releasing intra-vaginal device (CIDR-B) was inserted in the vagina and placed in situ for a period of 12 days and on the day of removal PGF2 (3 ml Ilerin i/m) was injected. In Control Group, no treatment was given. Blood samples were collected for progesterone estimation at the time of CIDR-B insertion (day 0), day 4 and 8 after CIDR-B insertion, on the day of CIDR-B removal (day 12), on the day of covering and day 12 after covering. At corresponding days, blood samples were also collected from Control Group. After CIDR-B removal, the reproductive performance of mares was recorded up to 20 days in terms of estrus induction response and pregnancy rates. In mares, which were having initial basal progesterone levels (1.64 0.19 ng/ml) on the day of device insertion, the levels significantly (p