Effect of different levels of zilpaterol hydrochloride in two days on-two days off feeding program on performance, carcass quality and blood metabolites in Japanese quails

The purpose of this study was to evaluate the effect of zilpaterol hydrochloride in two days on-two days off feeding program on performance, carcass quality and blood metabolites of Japanese quails. One hundred twenty eight, 26 days old male quails were assigned to four experimental groups with four replicates of 8 birds each. Diets were based on corn and soybean meal in finisher period (24% cp and 2900 kcal/kg of diet). The birds were supplemented daily with 0, 0.2, 0.225, or 0.25 mg of zilpaterol/kg of live weight. On day 47, 2 birds from each replicate were randomly selected for bleeding. After three days of zilpaterol withdrawal period (on day 50), two birds were slaughtered for carcass quality evaluation. Data were analyzed using the GLM procedure of SAS software. Zilpaterol hydrochloride supplementation significantly improved feed conversation ratio compared to the control group (P<0.05), while its effect on feed intake and weight gain were not significant (P>0.05). Carcass quality, (relative weights of legs, breast, liver, and fat pad) was not affected by Zilpaterol hydrochloride. Zilpaterol hydrochloride supplementation increased plasma glucose concentration compared to the control group, but it had no effect on plasma cholesterol and triglyceride concentrations.