The effect of ovulatory follicle size at the time of insemination onpregnancy rate in lactating dairy cows

Authors : Abdulkadir KESKİN, Gülnaz MECİTOĞLU, Ebru BİLEN, Bariş GÜNER, Abdülkadir ORMAN, Hayrettin OKUT, Ahmet GÜMEN

Pages : 68-74

View : 21 | Download : 9

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The aims of this study were to determine the factors that affect follicle size at the time of artificial insemination insert ignore into journalissuearticles values(AI); and to detect the relationship between ovulatory follicle size at the time of AI and pregnancy rate in dairy cows. A total of 1428 follicle size measurements were obtained from Holstein-Friesian insert ignore into journalissuearticles values(HF); and Swedish Red insert ignore into journalissuearticles values(SR); cows that were inseminated with the fixed-timed AI protocols used in this study. Follicle size was affected by breed insert ignore into journalissuearticles values(P = 0.0001);, milk production insert ignore into journalissuearticles values(P = 0.01);, parity insert ignore into journalissuearticles values(P = 0.05);, and season insert ignore into journalissuearticles values(P = 0.04);. Follicle size was greater insert ignore into journalissuearticles values(P = 0.0001); in the HF insert ignore into journalissuearticles values(15.55 mm); than the SR cows insert ignore into journalissuearticles values(14.88 mm);. Multiparous cows had larger insert ignore into journalissuearticles values(P = 0.04); follicles insert ignore into journalissuearticles values(15.35 mm); than the primiparous cows insert ignore into journalissuearticles values(15.07 mm);. Cows with follicle sizes between 13.5 and 17.5 mm were more likely to be pregnant than cows with other sizes follicles insert ignore into journalissuearticles values(P < 0.01);. Embryonic loss was lower insert ignore into journalissuearticles values(P < 0.01); in cows with follicle sizes between 13.5 and 16.5 mm. Thus, the follicle size was affected by breed, milk production, parity, and season. Pregnancy and embryonic loss in lactating dairy cows were significantly related to follicle size.
Keywords : Cow, follicle size, timed AI protocol, pregnancy rate