Gokhan  Dogruer, Mustafa Kemal  Saribay, Fikret  Karaca, Yasar  Ergun, 
    The Comparison of the Pregnancy Rates Obtained after the Ovsynch and Double Dose PGF<SUB>2&#945;</SUB> + GnRH Applications in Lactating Dairy Cows,
    Journal of Animal and Veterinary Advances,
    Volume 9,Issue 4,
    2010,
    Pages 809-813,
    ISSN 1680-5593,
    javaa.2010.809.813,
    (https://makhillpublications.co/view-article.php?doi=javaa.2010.809.813)
    Abstract: This study was carried out to compare the pregnancy rates in timed artificial inseminations after Ovsynch and PGF<SUB>2&#945;</SUB> + 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 &#956;g<SUP>-1</SUP> GnRH at day 0, 500 &#956;g<SUP>-1</SUP> PGF<SUB>2&#945;</SUB> at day 7 and 10.5 &#956;g<SUP>-1</SUP> GnRH at day 9 intramuscularly. The cows in PG group recieved 500 &#956;g<SUP>-1</SUP> PGF<SUB>2&#945;</SUB> two times with an interval of 14 days and 10.5 &#956;g<SUP>-1</SUP> GnRH intramuscularly 48 h after the second PGF<SUB>2&#945;</SUB> 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&gt;0.05). It was concluded that the programme consisted of 14 days interval double dose PGF<SUB>2&#945;</SUB> injections, GnRH applications 48 h following the second PGF<SUB>2&#945;</SUB> injection and timed artificial insemination 16-20 h after the GnRH injection could be an alternative to the Ovsynch programme in timed artificial inseminations.
    Keywords: Ovsynch;prostaglandin;timed artificial insemination;pregnancy;dairy;cow;Turkey