Livestock Studies 2017, Vol 57, Num, 1     (Pages: 018-024)

Annual Change of Reproductive Hormones in Angora Goat Bucks

Erkan Pehlivan 1 ,Hüseyin Polat 2 ,Gürsel Dellal 1

1 Ankara Üniversitesi Ziraat Fakültesi Zootekni Bölümü, Ankara
2 Aksaray Üniversitesi Fen Edebiyat Fakültesi Biyoteknoloji ve Moleküler Biyoloji Bölümü, Aksaray
- In this research, annual changes of melatonin, gonadotropin releasing hormone (Gn-RH), follicle stimulating hormone (FSH), luteinizing hormone (LH), estrogen, testosterone and progesterone were investigated on 7 heads of 1.5 years old Angora goat bucks. To determine hormones concentration, blood samples were taken from jugular vein of each goat in every month for a year. The blood samples were centrifuged at 4000xg for 5 min. and serum was stored at -20°C until analyses time. Hormone analysis in the serum were performed by enzyme immunoassay (EIA) method. Monthly climatic values were obtained from the Turkish State Meteorological Service and temperature-humidity index (THI) was calculated with climatic values. In the study, in order to determine any possible differences in the observed hormone concentrations with respect to months, repeated measures ANOVA analysis was performed. As a result of statistical analysis, significant differences (p<0.01) were found among the months for all hormonal parameters. According the results of this study, could be concluded that the releases of reproductive hormones was seasonally dependent and this releases were significantly influenced by climatic factors such as photoperiod and THI in Angora goat bucks. Keywords : Angora goat, reproduction, hormones, annual change, photoperiod