Dogruer, GokhanSaribay, Mustafa KemalKaraca, FikretErgun, Yasar2024-09-182024-09-1820101680-55931993-601Xhttps://hdl.handle.net/20.500.12483/11550This study was carried out to compare the pregnancy rates in timed artificial inseminations after Ovsynch and PGF(2 alpha) + 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 mu g(-1) GnRH at day 0, 500 mu g(-1) PGF(2 alpha) at day 7 and 10.5 mu g(-1) GnRH at day 9 intramuscularly. The cows in PG group recieved 500 mu g(-1) PGF(2 alpha) two times with an interval of 14 days and 10.5 mu g(-1) GnRH intramuscularly 48 h after the second PGF(2 alpha) 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 PGF(2 alpha) injections, GnRH applications 48 h following the second PGF(2 alpha) injection and timed artificial insemination 16-20 h after the GnRH injection could be an alternative to the Ovsynch programme in timed artificial inseminations.eninfo:eu-repo/semantics/openAccessOvsynchprostaglandintimed artificial inseminationpregnancydairycowTurkeyArticle948098132-s2.0-77953736630N/AWOS:000275982800031Q3