Study of serum growth hormone, 3,5,3 '-trixodothyronine, thyroxine, total protein and free fatty acids levels during parturition and early lactation in ewes

Abstract

Fifteen Chios pregnant ewes were used in the study. The ewes were fed hay and concentrated feed ad libitum. Water was provided ad libitum. Blood samples were collected from the jugular vein at parturition and day 15 after parturition. Concentrations of growth hormone (GH) were determined by an enzyme immunoassay. 3,5,3'-triiodothyronine (T-3) and thyroxine (T-4) contents were measured by radioimmunoassay with commercial kits. Concentrations of free fatty acids (FFA) and total protein were determined spectrophotometrically with commercial kits. GH, FFA and T-3 levels tended to be lower on day 15 after parturition, but no significant differences were found between two blood sampling days. T-4 and total protein levels tended to be higher on day 15 after parturition, but similarly, there were not significant differences between parturition and day 15 after parturition. In conclusion, serum GH, FFA, T-3, T-4 and total protein levels did not significantly change between parturition and day 15 after parturition. The obtained results may be accepted as reference values for ewes.