The Effect of Induction of ‎Hyperthyroidism and Hypothyroidism on ‎Performance, Blood and Reproductive ‎Parameters in Japanese Quail

This study was performed to evaluate the effects of hypothyroidism and hyperthyroidism on performance, blood and reproductive parameters in Japanese quail. 320 one-day-old quail chicks were used in a completely randomized design with 4 treatments and 4 replications. Treatments were included 1- untreated (control), 2- levothyroxine (70 μg / l), 3- propylthiouracil (15 mg / l) and 4- propylthiouracil first and then levothyroxine. Performance parameters were recorded weekly. On day 42 of rearing, one male and one female were selected from each replicate and blood samples were taken to evaluate blood parameters. On day 62 of rearing, the bird's eggs were collected and transferred to the incubator. Food conversion ratio, feed intake and weight gain were not affected by the treatments. In male blood serum, triglyceride concentration in all therapeutic treatments and alanine aminotransferase concentration in propylthiouracil-levothyroxine treatment significantly reduced (P≤0.05). In female birds, blood LDL concentration decreased in levothyroxine treatment compared to control and alanine aminotransferase increased in this treatment compared to other groups (P≤0.05). The highest serum alkaline phosphatase concentration of females was observed in propylthiouracil treatment (P≤0.05). Other blood biochemical parameters and fertility percentage were not affected by the treatments. The lowest percentage of total hatching and hatching of fertile eggs and the highest percentage of embryonic mortality were related to the treatment of propylthiouracil-levothyroxine (P≤0.05). In conclusion, induction of hyperthyroidism and hypothyroidism with drugs did not have a significant effect on most functional, reproductive and blood parameters in Japanese quail.