Laktasyondaki İneklerde Tohumlama Anında Azaltılan GnRH Dozunun Gebelik Oranı Üzerine Etkisi

Çalışma laktasyondaki ineklerde tohumlama anında uygulanan GnRH dozunun yarıya indirilmesinin gebelik oranı üzerine etkisini belirlemek amacıyla yapıldı. Araştırmada yaşları 3-6 arasında değişen, postpartum 80-120 günler arasında olan ve klinik olarak herhangi bir reprodüktif probleme rastlanılmayan 50 Holstayn ırkı inek kullanıldı. İneklerin östrüs göstermeleri için herhangi bir hormonal uygulama yapılmadı. Çalışma süresince östrüs belirtileri gösteren ineklerin ovaryum muayeneleri 6-8 MHz lineer problu real-time ultrason ile yapıldı ve ovaryumdaki mevcut foliküllerin çapı kaydedildi. Daha sonra bir gruba (grup I, n=25) suni tohumlama (ST) anında bir gonadotropin salgılatıcı hormon (GnRH) analoğu olan Buserelin asetat (Receptal®, İntervet) 2.5 mL kas içi uygulandı. Diğer gruba (grup II, n=25) ise ST anında 1.25 mL Buserelin asetat kas içi uygulandı. Folikül çapları grup I ve II’de sırasıyla 12.28±0.37 mm, 12.24±0.44 mm olarak kaydedildi. Gebelik oranları grup I ve II’de sırasıyla %80 (20/25), %72 (18/25) olarak belirlendi (P>0.05). Sonuç olarak, ineklerde gebelik oranlarının artırılması amacıyla ST sırasında uygulanan GnRH’nın dozunun yarıya indirilmesinin gebelik oranlarını etkilemediği görüldü.

Anahtar Kelimeler:

İnek, GnRH, Gebelik oran

The Effect of Reduced Dose of GnRH Administered at the Time of Insemination on Pregnancy Rate in Lactating Dairy Cows

This study was carried out to determine the effect of reducing half dose of GnRH performed immediately at the time of artificial insemination on pregnancy rate in lactating dairy cows. The study was conducted on 50 Holstein cows aging between 3-6 years old, and on 80-120 days postpartum without reproductive problems. No hormonal application was carried out for ensuring estrous in cows. The ovarian examinations of the cows showing estrous symptoms were performed by real-time ultrasound with 6–8 MHz lineer probe and the diameters of the follicles were recorded. The cows in Group I (n=25), a gonadotropin releasing hormone (GnRH) analogue, buserelin acetate (Receptal®, İntervet) recieved 2.5 ml of GnRH intramucularly just at the time of artificial insemination. Group II recieved 1.25 mL of GnRH, intramuscularly immediately at the same time. The diameters of follicles at the time of inseminations were detected as 12.28±0.37 mm, 12.24±0.44 mm in the group I and group II respectively. The pregnancy rates were 80% (20/25) and 72% (18/25), in group I and group II respectively (P>0.05). It was concluded that reducing the half dose of GnRH, which is performed to increase the pregnancy rate in cows immediately at the time of insemination, did not affect the pregnancy rate.

Keywords:

Cow, GnRH, Pregnancy rate,

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