Gonadotrophin stimulation of ewes that are not pregnant following multiple matings during the season

Authors : Şükrü DURSUN

Pages : 39-43

View : 18 | Download : 5

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :In this study, the aim was to obtain pregnancy following synchronization and to increase profitability in ewes that did not become pregnant during the breeding season after at least 3 matings. Nonpregnant Middle Anatolian Merino ewes insert ignore into journalissuearticles values(n = 117); were given a progesterone sponge for 9 days. At the time of sponge removal, the ewes received 250 IU pregnant mare serum gonadotropin insert ignore into journalissuearticles values(PMSG); + 125 µg prostaglandin F2α insert ignore into journalissuearticles values(PGF2α);. Two days later, they were injected with either human chorionic gonadotropin insert ignore into journalissuearticles values(hCG); insert ignore into journalissuearticles values(Group I, n = 48); or gonadotropin-releasing hormone insert ignore into journalissuearticles values(GnRH); insert ignore into journalissuearticles values(Group II, n = 43);, or remained as a control insert ignore into journalissuearticles values(Group III, n = 26);. The ewes were allowed to mate at estrus following the PGF2α injection. Pregnancy diagnosis was performed on day 30 after mating by ultrasonography. Group ratios for estrus insert ignore into journalissuearticles values(58.3%, 55.8%, 53.8%);, conception insert ignore into journalissuearticles values(78.6%, 87.5%, 14.3%);, lambing insert ignore into journalissuearticles values(90.9%, 90.5%, 50.0%);, multiple births insert ignore into journalissuearticles values(15.0%, 31.6%, 0.0%);, and average lamb number for birth insert ignore into journalissuearticles values(1.15%, 1.31%, 1.0%); were reported. In conclusion, the gonadotropin-supplemented protocols used here were found to be useful in ewes that were not pregnant after multiple matings during the breeding season in increasing the profitability of flocks with this problem.
Keywords : Breeding season, gonadotropin releasing hormone, human chorionic gonadotropin, Merino