STRATEGIC USE OF GONADOTROPHIN AND PROSTAGLANDIN FOR MANAGING THE REPEAT BREEDING SYNDROME IN A DAIRY FARM

Abstract

A total number of fifty-three (53) dairy cows were used i) to detect the causes of repeat breeding syndrome of dairy cows in a farm, ii) to evaluate the responses of gonadotrophin releasing hormone and prostaglandin for management of repeat breeding syndrome and iii) to evaluate the conception rate in hormonally treated cows after inseminated naturally and artificially. All experimental animals were treated with three protocols: Select synch protocol, Ovusynch protocol and PGF2α plus PGF2α injection selected on the basis of findings of rectal palpation. The estrus cows were inseminated naturally or artificially. Pregnancy was confirmed by non-return to estrus and rectal palpation. Among all the cows, 54.72 % cows had cystic ovarian degeneration diagnosed by rectal palpation. The estrous response rate in Select synch, Ovusynch, andPGF2α plus PGF2α protocols were 100%, 100% and 89.47%, respectively. The mean time of onset of estrous was 49 ± 3.41 hr. in Select synch, 48.6 ± 2.98 hr. in Ovusynch and 44.26 ± 15.8 hr. in PGF2α plus PGF2α protocol, respectively. There was no significant difference (P>0.05) among the groups of dairy cows on the time of onset of estrous. The mean time of duration of estrous in Select synch, Ovusynch, and PGF2α plus PGF2α protocols were 40.1 ± 3.85 hr., 47.1 ± 5.61 hr. and 37.5 ± 13.44 hr., respectively. There was no significant difference (P>0.05) among the groups on both onset of estrous and duration of estrous. Poor conception rates following induction of estrus by Select synch, Ovusynch and PGF2α plus PGF2α protocol in dairy cows inseminated artificially were found, whereas the conception rate following induction of estrous by three protocols in naturally inseminated dairy cows was 100%. The overall conception rate of in cows (n=26) inseminated naturally was 100% and artificially (n=25) were only 8%. There was significant (P<0.05) difference on conception rate of dairy cows between artificial insemination and natural service groups. Though the estrus responses to hormonal treatment were better, however, conception rate was significantly lower by artificial insemination than natural. It is suggested that it is better to ensure the semen quality and AI technician skillness before insemination at Small and large scale dairy farms.