Progesterone concentration in milk and blood serum and reproductiveefficiency of cows after Ovsynch treatment

Authors : Dejan VUKOVIC, Aleksandar BOZIC, Renata RELIC, Blagoje STANCIC, Dragan GVOZDIC, Denis KUCEVIC

Pages : 75-80

View : 16 | Download : 9

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :An experiment was conducted to investigate the effects of hormonal synchronization of ovulation on progesterone concentrations in milk and blood serum and on reproductive performance. Sixty Holstein-Friesian cows averaging 8000 L over 305 days of lactation were divided into 2 groups of 30 animals. One-factor ANOVA and a t-test of progesterone concentrations in venous serum and milk revealed that the lowest concentrations of progesterone in milk insert ignore into journalissuearticles values(Ovsynch 5.8 ± 1.0 ng/mL; control 4.5 ± 0.6 ng/mL); and blood serum insert ignore into journalissuearticles values(Ovsynch 1.3 ± 0.9 ng/mL; control 1.4 ± 0.5 ng/mL); in both groups were found on the day of estrus or artificial insemination insert ignore into journalissuearticles values(AI); insert ignore into journalissuearticles values(both P < 0.05);. Increases in the concentrations of progesterone in milk insert ignore into journalissuearticles values(Ovsynch 17.6 ± 4.3 ng/mL; control 10.5 ± 1.9 ng/mL); and blood serum insert ignore into journalissuearticles values(Ovsynch 3.6 ± 1.1 ng/mL; control 4.0 ± 1.0 ng/mL); were observed on day 7 after AI insert ignore into journalissuearticles values(both P < 0.05);. Concentrations of progesterone in milk and blood serum in nonpregnant cows were reduced on day 21 after AI. Assessment of reproductive performance revealed that the application of treatment shortened the duration of the service period insert ignore into journalissuearticles values(Ovsynch 76 days; control 83 days); and the calving interval insert ignore into journalissuearticles values(Ovsynch 376 days; control 382 days);.
Keywords : Ovsynch, synchronization of estrus, dairy cows, reproductive parameters