Effectiveness of Different Progesterone Analogues and GnRH on Reproductive Parameters in Nulliparous Saanen Goats at the End of the Transition Period

Abstract

The objective of this study was to compare the efficacy of diff erent estrus synchronization protocols on reproductive parameters in nulliparous Saanen goats at the end of the transition period. In this experiment, 71 nulliparous Saanen does were used and divided into four treatment groups as norgestomet implant plus GnRH (Imp-G), norgestomet implant (Imp), FGA sponge plus GnRH (Spo-G), and FGA sponge (Spo). The progestagen treatments were administered for 11 days. At progestagen withdrawal, all does were injected with 360 IU of eCG and 125 μg of PGF2α. At the end of the treatments, all the does were joined with fertile bucks. There were no significant diff erences (P>0.05) in reproductive parameters among the treatments groups. Does were in estrus within 29.2±0.36 h for all the treatments combined. It was concluded that, the use of norgestomet implants and FGA sponges in combination with eCG and PGF2α were eff ective for estrus response, onset of estrus, fecundity, prolificacy, and fertility in nulliparous Saanen does at an age of 7-9 months under local conditions at the end of the transition period also GnRH was found to be ineff ective in increasing the reproductive parameters. Keywords: Estrus synchronization, GnRH, Nulliparous Saanen goat, Progestagens, Transition period Geçiş Döneminin Sonundaki Nullipar Saanen Keçilerinde Farklı Progesteron Analogları ve GnRH Uygulamalarının Reprodüktif Parametreler Üzerine EtkinliğiÖzet Çalışmada, geçiş döneminin sonundaki nullipar Saanen keçilerine uygulanan farklı östrus senkronizasyon protokollerinin reprodüktif parametreler üzerine etkilerinin karşılaştırılması amaçlandı. Çalışmada 71 adet nullipar Saanen keçisi kullanıldı ve keçiler rastgele 4 gruba ayrıldı: norgestomet implant + GnRH (Imp-G), norgestomet implant (Imp), FGA sünger + GnRH (Spo-G) ve FGA sünger (Spo). Progesteron tedavileri 11 gün süreyle uygulandı. Progesteron tedavilerinin son günü tüm keçilere 360 IU eCG ve 125 μg PGF2α yapıldı. Tedavilerin sonunda tüm keçiler fertil tekeler ile çiftleştirildi. Tedavi grupları arasında reprodüktif parametreler açısından istatistiksel bir farkın olmadığı belirlendi (P > 0.05). Tüm tedaviler değerlendirildiğinde keçilerin 29.2±0.36 saat içinde östrus gösterdiği saptandı. Sonuç olarak, yerel çevre şartlarında yetiştirilen ve geçiş sezonunun sonunda bulunan 7-9 aylık nullipar Saanen keçilerinde norgestomet implant ve FGA süngerin eCG ve PGF2α ile birlikte kullanılmasının östrus oranı, östrus başlangıcı, fekundite, prolifikasyon ve fertilite oranları bakımından etkili olduğu; GnRH kullanımının ise fertilite parametrelerinde artış sağlamadığı belirlendi.

The Effect of Gonadotropin Releasing Hormone Administration on Fertility and Embryonic Loss in Goats during the Anoestrus Period

“…In the same way, Uslu and Gülyüz [33] stated that GnRH injection after breeding has a positive effect on the pregnancy rate. In contrast, some studies have shown that hCG and GnRH injection after breeding are not beneficial for increasing fertility or the pregnancy rate [2,4,26,31]. This study does not support the hypothesis that GnRH treatment at breeding and after breeding prevents embryonic loss and improves reproductive performance.…”

“…Blood samples for progesterone measurement were taken into anticoagulated tubes 4 by jugular vena puncturing on days 3, 6, 7, 10, 13, 16 and 19 days after breeding from 10 randomly chosen goats in all groups. Blood sampling was also performed for all goats on day 21.…”