Effect of L-Thyroxine on Some Blood Parameters in Broiler Chicks (Gallus gallus) of Different Ages

The effect of intraperitoneal administration of a single dose (1μg/g) of thyroxine (T4) after 24, 48 and 98 hours on plasma total proteins, albumin fraction, uric acid, glucose, triglycerides and cholesterol has been investigated in broiler (Hubbard) chicks of 15, 25 and 35 days of age. Thyroxine treatment resulted in a significant decrease of plasma proteins after 96 hours of the experiment in 25 days old chicks and after 48 hours in birds of 35 days of age. The plasma albumin was significantly lowered in all experimental animals of different age groups. Thyroidal treatment showed a decreasing trend of plasma uric acid levels in chicks of different age groups. However, there was an exceptional increase of uric acid values after 24 hours of the experiment in 15 days old chicks. Plasma glucose values exhibited a decreasing trend in 25 days and 35 days old experimental birds throughout the experimental period. The trend for plasma glucose values in 15 days old experimental birds was found to be opposite to those of relatively advance age. Thyroxine treatment resulted in a decrease in plasma triglycerides in broilers of all age groups. There was an increasing trend in plasma cholesterol levels in thyroxine administered birds of different age groups. The increase in cholesterol values was found to be significant at 24 hours and it persisted up to 48 hours of the experiment in 15 days old chicks.