Profile of thyroid hormone in male Layer chickens given by testosterone

The aim of the study was to evaluate the administration of Testosterone toward growth, levels of Triiodothyronine (T3) and Thyroxine (T4) in male Layer chicken. Forty male
Layer chickens strain Isa Brown was used in this study. Chickens were divided into 2 groups, control and treatment groups (given commercial testosterone) at a dose of 3 mg/kg body weight/day for 5 weeks. The results showed the growth of chickens treated by Testosterone increased significantly from week 1 to week 5 with a range between 59.43 ± 0.76 grams to 332.50 ± 0.79 grams, (P < 0.05). However, due to treatment differences, the results obtained
that the administration of Testosterone cannot accelerate the growth of male Layer chickens (P > 0.05). Even in the week 3 and week 4, the growth rate is lower than the control. The levels reduction of T3 start from 4.91 ± 0.98 ng/mL to 1.38 ± 0.09 ng/mL, while T4 levels start from
1.01 ± 0.85 ug/mL to 0.84 ± 0.21 ug/mL. It could be concluded that the administration of testosterone can reduce T3 and T4 levels but cannot accelerate the growth rate of male Layer chickens.