Effect of iodine supplementation on growth performance, carcass traits and levels of thyroid hormone were studied in broilers. Five hundred 1-d-old female broiler chicks were randomly divided into 5 groups (100 birds / group) with 4 replicates each .from d1, the diet were supplemented with calcium iodate at levels of 0 , 0.74 , 1.48 , 2.22 and 2.96 mg/kg of feed respectively. The birds were reared to 49d of age under standard conditions. Average feed intake, body weight gain and feed conversion ration of the broilers during 0 to 3 wk, 3 to 6wk and 6 to 7 wk were measured. Blood samples were collected at the end of each period from wing vein.T3 and t4 were measured by radioimmunoassay (RIA). Four birds per group were slaughtered at 49 d. Feed intake body weight gain and feed conversion ratio were affected by added levels of calcium iodate during the starter (0-21) period. Iodine supplementation did not significantly affect the carcass traits. adding levels of calcium iodate were significantly increased the concentration of thyroxine at 42 days of age. T3 hormone was not significantly affected by adding calcium iodate in to the diets at 21 , 42 and 49 days of age .The result from current study suggest that the addition of calcium iodate to broiler diets has not benefit effect on broiler performance
