ANNUAL CHANGES OF THYROID STIMULATING HORMONE, THYROXINE, TRIIODOTHYRONINE AND CORTISOL HORMONES IN ANGORA GOATS - E. Pehlivan; G. Dellal (Journal of Animal and Plant Sciences, 2017)
In this research, annual changes of thyroid stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3) and cortisol hormones were studied on 13 heads of 1.5 years old Angora goat (6 heads of female and 7 heads of male). The blood samples (10 mL) were taken from vena jugularis of each goat in every month for a year in order to determine hormone levels. The blood samples were centrifugated at 4000xg for 5 min. for hormone analyzes. Sera were stored at -20 °C until analyzes time. Hormone analyzes in the serum were performed by enzyme immunoassay (EIA) method in the Reproductive Biology and Animal Physiology Laboratory at Ankara University, Faculty of Agriculture, Department of Animal Science. Monthly climatic values were obtained from the Turkish State Meteorological Service and temperature-humidity index (THI) was calculated with these values. The interaction between gender and month was not significant with respect to all hormones levels. In addition, there was no significant differences among the months for TSH levels, while there were significant (P<0.01) differences among the months for T4, T3 and cortisol levels in Angora goats. Based on the results of this research, it was concluded that the release of T4, T3 and cortisol hormones in Angora goats depend on the season and are affected by THI changes.
Keywords: journal article; hormonal changes; seasons; heat stress; thyroid