Siklik ve asiklik anöstrüslu ineklerde Ovsynch ve Ovsynch+Cosynch uygulamalarının gebelikler üzerine etkilerinin karşılaştırılması

Bu çalışmanın amacı doğum sonrası kızgınlıkları gözlenemeyen sütçü ineklerde, GnRH + PGF2C1 + GnRH ve ikinci GnRH uygulamasını izleyen 16. saatte tohumlama (Ovsynch yöntemi), GnRH + $PGF_2\alpha$ + GnRH ve ikinci GnRH uygulaması ile aynı anda ve 16 saat sonra olmak üzere çift tohumlama (Cosynch yöntemi + Ovsynch yöntemi) şeklindeki iki farklı hormonal uygulama metodununun ilk tohumlama gebelik oranı üzerine etkilerini karşılaştırmaktır. Laktasyonda bulunan ve kızgınlıkları gözlenemeyen 84 baş sütçü inek tedavi grupları içerisine rasgele olarak dağıtıldı. Grup I (Ovsynch) (N: 41)'deki ineklere, 0. günde 10 ug busereline acetate (GnRH), yedinci günde 25 mg dinoprost trometamine ( $PGF_2\alpha$ analoğu), dokuzuncu günde 10 ug busereline acetate uygulandı ve ikinci GnRH uygulamasını izleyen yaklaşık 16. saatte sun'i tohumlama yapıldı. Grup II (Ovsynch + Cosynch) (N: 43)'deki ineklere, 0. günde 10 ug busereline acetate (GnRH), yedinci günde 25 mg dinoprost trometamine (PGF2a analoğu), dokuzuncu günde 10 ug busereline acetate uygulandı ve ikinci GnRH uygulaması ile aynı anda ve izleyen yaklaşık 16. saatte olmak üzere çift sun'i tohumlama yapıldı. Gebelikler sun'i tohumlamaları izleyen 50. günde rektal muayene ile belirlendi. İlk tohumlama gebelik oranları grup I ve II için sırasıyla % 58.5 ve % 44.1 olarak tespit edildi. İlk tohumlama gebelik oranları açısından grup I ve grup II arasında istatiksel fark belirlenmedi. İlk tohumlama gebelik oranı grup Fde grup H'ye göre daha fazla olma eğilimindeydi. Bununla birlikte grup Il'deki asiklik inek oranı grup I'den daha fazlaydı. Sonuç olarak grup H'de yapılan çift tohumlama grup I'deki tek tohumlamaya göre ilk tohumlama gebelik oranları üzerine ilave bir katkı yapmadı. Büyük bir olasılıkla ilk tohumlama gebelik oranındaki farklılık grup Il'deki asiklik inek oranının grup I'deki asiklik inek oranına göre fazla olmasından kaynaklandı.

Anahtar Kelimeler:

PMSG, suni tohumlama, sığır, süt sığırı, süt ineği, kızgınlık, prostaglandinler, GnRH, anöstrüs, inek, metodoloji, gebelik, gebelik oranları

Comparison of effects on pregnancy rates of ovsynch and cosynch+osvynch administrations in cyclic or noncyclic anestrus cows

This investigation was carried out in order to compare effect of two different treatment methods on the first service pregnancy rate in postpartum unobserved estrus dairy cows. These methods were GnRH + $PGF_2\alpha$ + GnRH and artificial insemination (TAI) at 16th hours after the last GnRH injection (Ovsynch protocol), GnRH + $PGF_2\alpha$ + GnRH and double TAI either concurrently and at 16th hours after the second GnRH injection (Cosynch + Ovsynch). A total of 84 unobserved estrus lactating dairy cows were randomly assigned into two groups. Cows in group I (Ovsynch) (N: 41) at days 0, 7 and 9 were treated with 10 ug busereline acetate (GnRH), 25 mg dinoprost trometamine ( $PGF_2\alpha$ analogue) and 10 ug busereline, respectively, and timed artificial insemination (TAI) occured approximately at 16th hours after the second GnRH injection. Cows in group II (Ovsynch + Cosynch) (N: 43) at days 0, 7 and 9 were treated with lOmcg Busereline acetate (GnRH), 25mg dinoprost trometamine ( $PGF_2\alpha$ analogue), lOmcg Busereline, respectively, and double TAI either concurrently or at 16th hours after the last GnRH injection. Pregnancy testing was conducted by rectal palpation of uterus on days 50 after AI. First service pregnancy rates for group I and II were determined as 58.5 % and 44.1 % respectively. There was no statistical difference for the first service pregnancy rates between the groups. In group I the first service pregnancy rate tended to be higher than group II. Hovewer, there were more acycling cows in group II than in group I. As a result of this study, it was found that in group II double AI treatment to the cows did not made an additional contribution on the first service pregnancy rate. Hovewer, the difference for the first service pregnancy rates in the groups may be resulted from higher acycling cows rate in group II than in group I.

Keywords:

PMSG, artificial insemination, cattle, dairy cattle, dairy cows, oestrus, prostaglandins, GnRH, anoestrus, cows, methodology, pregnancy, pregnancy rate,

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