Estrus induction and fertility response in delayed pubertal Kankrej heifers treated with norgestomet ear implant

Aim: The study was undertaken to find out the estrus induction and fertility response in delayed pubertal Kankrej heifers treated with norgestomet ear implant. Materials and methods: Total eighteen anoestrus Kankrej heifers of delayed puberty weighed above 250 kg and attained between 30 to 36 months of age were selected and divided in to three groups of six animals each at random to conduct the experiment. Animals in group 1 were implanted Crestar ear implant for 9 days. In addition to this, group 2 received 500 IU of PMSG on the day of implant removal. In group 3, treatment protocol remained same as in group 2, but Inj. Receptal @ 2 ml was given additionally at the time of breeding. Results: All the animals exhibited estrus with average duration of 25.41+ 0.94, 21.95+ 0.20 and 22.68 + 1.46 hours between implant withdrawal and estrus induction in group 1, 2 and 3, respectively. The duration of estrus was significantly (P<0.05) longer (25.61+ 2.95 hours) in group 2, followed by group 1 (18.88 + 1.45 hours) and group 3 (13.48 + 1.92 hours). The pregnancy rate at induced estrus was 33.33 percent in group 2. In group 1 and group 3 none of the heifers found pregnant at induced estrus. The overall conception rate was maximum in group 2 (66.67 percent) followed by group 3 (50 percent) and rd group 1 (33.33 percent) after the 3 service. Conclusion: Although the conception rate at induced estrus was lower, norgestomet ear implant could be utilized to induced estrus in delayed pubertal cow heifers.