Authors : Gokhan Dogruer, Mustafa Kemal Saribay, Fikret Karaca and Yasar Ergun
Abstract: This study was carried out to compare the pregnancy rates in timed artificial inseminations after Ovsynch and PGF2α + GnRH applications on lactating dairy cows. The research was conducted in a commercial dairy farm on 84 lactating Holstein cows which the ages were ranging between 3-5 years old and between 80-120 days postpartum. The cows were randomly assigned to two groups as Ovsynch (n = 42) and Prosta Glandin (PG) (n = 42). The cows in Ovsynch group recieved 10.5 μg-1 GnRH at day 0, 500 μg-1 PGF2α at day 7 and 10.5 μg-1 GnRH at day 9 intramuscularly. The cows in PG group recieved 500 μg-1 PGF2α two times with an interval of 14 days and 10.5 μg-1 GnRH intramuscularly 48 h after the second PGF2α injection. Artificial inseminations were applied to the cows in both of the groups between 16-20 h after the GnRH injections. The pregnancy diagnosis was performed 30 days after the artificial inseminations by ultrasonography. The pregnancy rates were determined as 35.7% (15/42) in Ovsynch group and 47.6% (20/42) in PG group. Although, the pregnancy rate were higher in PG group than the Ovsynch group the differrence was not statistically important (p>0.05). It was concluded that the programme consisted of 14 days interval double dose PGF2α injections, GnRH applications 48 h following the second PGF2α injection and timed artificial insemination 16-20 h after the GnRH injection could be an alternative to the Ovsynch programme in timed artificial inseminations.
Gokhan Dogruer, Mustafa Kemal Saribay, Fikret Karaca and Yasar Ergun, 2010. The Comparison of the Pregnancy Rates Obtained after the Ovsynch and Double Dose PGF2α + GnRH Applications in Lactating Dairy Cows. Journal of Animal and Veterinary Advances, 9: 809-813.