Diurnal variations in serum biochemical parameters and their correlations with thyroid hormones in ostrich chicks (Struthio camelus)

The present study aimed to examine variations in serum biochemical parameters to provide data about the diurnal variation of biochemical parameters in ostriches. This study was performed using blood samples from eight healthy male ostriches, (3 months old), which were in good condition and clinically normal. Diurnal variation of serum biochemical parameters was determined by daily blood collections over 9 days in summer at the School of Veterinary Medicine, Shiraz University. In serum samples nonelectrolytes (total protein, albumin, glucose, cholesterol, triglyceride, HDL cholesterol, creatinine, urea nitrogen, and uric acid), electrolytes (calcium, inorganic phosphorus, sodium, and potassium), enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and creatin kinase (CK)), and hormones (triiodothyronine (T 3 ) and thyroxine (T 4 )) were measured by validated standard methods. Most of the study variables showed no significant variations during the study period. However, for blood urea nitrogen, glucose, ALT, K, HDL cholesterol, and CK, significant changes were observed. Correlation coefficients showed significant association of T 4 with Na ( r = 0.38, P = 0.001), glucose ( r = −0.25, P = 0.03), calcium ( r = −0.28, P = 0.02), uric acid ( r = 0.26, P = 0.03), and creatinine ( r = −0.25, P = 0.03). Regarding T 3 , significant correlation with Na (−0.27, P = 0.02) was observed.