Effects of duration of zilpaterol supplementation on growth-performance, dietary energetics, carcass characteristics, and meat quality of crossbred yearling heifers slaughtered at lighter, less-than-mature final body weight (460 kg)

摘要: ObjectiveOur objective was to examine the effects of duration of zilpaterol hydrochloride (ZH) supplementation on growth performance, estimated dietary energetics, carcass characteristics, and meat quality in crossbred yearling heifers when slaughtered at lighter, less-mature final weight.Materials and MethodsTreatments consisted of a finishing diet based on steam-flaked corn supplemented with (1) 0 ZH (negative control); (2) 0.15 mg of ZH/kg of live weight supplemented for 20 of the final 23 d of the finishing period; (3) 0.15 mg of ZH/kg of live weight supplemented for 25 of the final 28 d of the finishing period, or (4) 0.15 mg of ZH/kg of live weight supplemented for 30 of the final 33 d of the finishing period.Results and DiscussionDuration of ZH supplementation did not affect (P ≥ 0.15) any of the variables measured. Compared with the control, ZH increased (P ≤ 0.02) carcass-adjusted weight gain, G:F, and …