A.K. Zonturlu  , F. Aral  , U. Yavuzer  , 
    Effect of Different Method GnRH-PGF<SUB>2 </SUB> Treatment on Induced of Estrus and Pregnancy in Breeding Season in Awassi Ewes,
    Journal of Animal and Veterinary Advances,
    Volume 8,Issue 4,
    2009,
    Pages 660-663,
    ISSN 1680-5593,
    javaa.2009.660.663,
    (https://makhillpublications.co/view-article.php?doi=javaa.2009.660.663)
    Abstract: The object of this study was to investigate, the effect of PGF<SUB>2α</SUB> administrated on 5 and 7 d following GnRH treatment on estrus and pregnancy during the breeding season in awassi ewes. A total of 60 ewes 3-5 years old were used in this experiment. The ewes were divided into 3 groups (20 ewes/group) in breeding season. First group (control) was treated with the PG-10 day protocol consisting of 2 intramuscular (i.m.) doses of PGF<SUB>2α</SUB> analogue (250 μg of D-Cloprostenol/dose). The second group received intramuscular injection of GnRH analogue (busereline) and 5 day later an i.m. injection of PGF<SUB>2α</SUB>. In the 3 groups were treated with GnRH followed, 7 days later, by an i.m. injection of 250 μg of prostaglandin F<SUB>2α</SUB>. After the detection of estrus, the ewes were inseminated with 0.2 mL fresh sperm. Pregnancy was determined using ultrasonography on day 30 after the AI. Estrus response was 90% in Group 1, 90% in Group 2 and 35% in Group 3 (p<0.001). The pregnancy rate was 77.8% in Group 1, 83.3% in Group 2 and 42.8% in Group 3 (p<0.05). Lambing rate was 77.8% in Group 1, 83.3% in Group 2 and 42.8% in Group 3 (p<0.05). These results suggest that effect of induction estrus and pregnancy and lambing rate after GnRH and 5 days later an i.m. injection of prostaglandin F<SUB>2α </SUB>were higher than GnRH and PGF<SUB>2α </SUB>treatment followed 7 days injection of PGF<SUB>2α</SUB>. But comparable to PGF<SUB>2α</SUB> treatment with 10 days intervals.
    Keywords: Ewes;GnRH;PGF2;estrus induction;intramuscular;ultrasonography