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Zilpaterol hydrochloride improves growth performance of meat producer Japanese quails
Zilpaterol hydrochloride (ZH) is a beta-adrenergic agonist that was approved in México (2002) and the United States (2006) to promote growth and carcass dressing in beef cattle. However has been tested in other species such as lambs and poultry. The objective of this experiment was determinate the effect of zilpaterol hydrochloride supplementation during 21 d on growth performance of meat producer Japanese quail (Coturnix coturnix japonica). Two hundred-twenty Japanese quails (both sex; 90.3 ± 1.19 g) were distributed in 20 birdcages with four treatments (5 birdcages by treatment). Treatments consisted in different doses (0, 0.20, 0.25, and 0.30 mg/kg of live weight/d) of zilpaterol hydrochloride supplementation, the basal diet contained 55% ground corn grain and 35% soybean meal (24%CP and 2.9 Mcal/kg of ME). Quails were weighted weekly and adjusted zilpaterol dose. The results were analyzed with completely randomized design and comparing means of treatments with orthogonal contrasts and orthogonal polynomials. Zilpaterol supplementation increased final live weight (5.6 %; P≤0.01), total weight gain (9.7%; P≤0.01), feed conversion (6.1 %; P≤0.01) and feed intake (2.8 %; P=0.02). Similarly, supplementation with 0.30 mg/kg of live weight increases the final live weight, total weight gain and feed conversion (P≤0.01) when compared with control treatment, however this dose showed no changes in feed intake (P=0.24). No significance difference (P≥0.21) were showed in all variables when compare minimum and maxim dose (0.20 vs 0.30 mg/kg of live weight), neither differences were detected for linear (P≥0.25) and quadratic (P≥0.14) analysis. These results indicated that zilpaterol supplementation in meat producer Japanese quail improve the growth performance without changes between doses. Levels below 0.20 mg/kg live weight need to be tested to determine the max inclusion rate needed.
Keywords:
Zilpaterol hydrochloride, Coturnix coturnix japonica, growth performance