Effect of Different Zilpaterol Hydrochloride Levels and Feeding Methods on the Growth Performance, Carcass Traits and Blood Parameters of Male Japanese Quails During Two Weeks of the Finishing Period

ABSTRACT The objective of this study was to determine the effects of different zilpaterol hydrochloride (ZH) levels and feeding methods on the growth performance and carcass traits of Japanese quails. In this trial, 224 male quails with 34 days of age were distributed into seven treatments. A factorial arrangement with three ZH levels (0.2, 0.225, and 0.25 mg zilpaterol/kg of live weight&#8722;1) × two feeding methods (ZH supplementation daily or every two days) plus a control treatment (no ZH supplementation) was applied. The weight gain of birds fed ZH every two days was significantly higher than those fed ZH daily during the period of 41-47 days (p=0.03). During the period of 34-40 days, ZH-supplemented birds presented higher weight gain (p<0.001) and better feed conversion ratio (p=0.005) compared with the control group. Moisture, protein, ash, and cholesterol levels of the combination of breast and leg were not affected (p&#8805;0.10) by zilpaterol supplementation. Leg muscle fat and protein contents of control birds were higher and lower compared with ZH-supplemented birds, respectively (p=0.002 and p=0.05). In conclusion, ZH supplementation in the diet of male Japanese quail improved growth performance during the finishing period (34-40d), and the most economical level of ZH is 0.2 (mg/kg of LW&#8722;1 d&#8722;1), when supplemented every two days