Effect of zilpaterol hydrochloride on animal performance and carcass characteristics in sheep: A meta-analysis

Abstract

The present study constitutes a meta-analysis of the use of zilpaterol hydrochloride (ZH) in sheep production (18 studies, n = 724 animals were evaluated), focused in its effects on productive performance and carcass characteristics in sheep who were given ZH in different doses (control 0, ≤0.50 and ≥0.54 mg/kg raised to the power 0.75 body weight (BW)). The analysis of the data assembled in the database was conducted by a statistical meta-analysis based on mixed model methodology. Results on weight gain were higher (P < 0.03) for the group supplemented with ≥0.54 mg vs. Control treatment, feed conversion improved (P < 0.01) with the inclusion of ZH compared with the control group. Carcass yield and Longissimus dorsi area showed no differences (P > 0.05) between treatments, fat content in the carcass diminished in a linear effect (P = 0.02) with the inclusion of ZH. The results show a positive effect on improving animal performance, mainly in the characteristics on the fat deposition. The optimal dose varies depending on the variable to improve, ranged in 0.24 up to 1.21 mg ZH/kg BW0.75 to reduce fat and carcass get leaner or increase average daily gain, respectively.