M. Ahmad, N. Ahmad, I. Ahmad, N. Akhtar and S. Ali

Department of Animal Reproduction, University of Agriculture, Faisalabad-38040, Pakistan

    In this study 215 buffaloes and 180 cows with the history of repeat breeding and prolonged oestrus period (>24 hours) were used. All of the animals had repeated at least twice. A total of 95 animals (50 buffaloes and 45 cows) were inseminated once, 12-18 hours after the start of oestrus and were kept as control, while 165 buffaloes and 135 cows were divided into two treatment groups. In group I, 70 buffaloes and 55 cows were inseminated twice, first at 12-18 hours after the start of oestrus and then 12-24 hours later. In group II, 95 buffaloes and 80 cows were inseminated once at 12-18 hours after the start of oestrus. These animals were then subjected to forced racing for at least 30 minutes. In control group, 18 buffaloes (36%) and 15 cows (33.33%) were found to be pregnant 60 days after insemination. In treatment group I, 36 buffaloes (51.43%) and 30 cows (54.55%), whereas in group II, 70 buffaloes (73.68%) and 58 cows (72.50%), were observed to be pregnant. These results indicate that forced racing may be a good practical and economical tool to improve conception rate in repeat breeder animals where the problem is due to delayed ovulation.

Key words: Stress, conception rate, repeat breeding, buffaloes, cows.