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 BW 0.75 to reduce fat and carcass get leaner or increase average daily gain, respectively.

Comparative evaluation of supplemental zilpaterol hydrochloride sources on growth performance, dietary energetics and carcass characteristics of finishing lambs

“…Zilpaterol is not currently labeled as a feed additive for lambs. The numerous studies conducted thus far in feedlot lambs adopted the labeled dosage as indicated for feedlot cattle [3,5,6,18].…”

“…Increased HCW, LM area, and dressing percentage, and reduced backfat thickness with ZH supplementation has been a consistent response in feedlot lambs [18,21]. Increased LM area is partially explained by the greater ADG [22], whereas the increased dressing percentage is expected due to greater carcass protein accretion with no change in digestive tract fill [6,23].…”

Effect of Zilpaterol Hydrochloride on Performance and Meat Quality in Finishing Lambs

“…However, lambs from those breeds have a lower growth rate, carcass yield, and meat quality compared with lambs from wool breeds [2]. The livestock and meat industry is constantly looking for alternatives to promote fast and efficient growth of livestock, and improve the carcass yield, i.e., increasing longissimus thoracis et lumborum (LTL) muscle area [3] or diminishing the fat content in the carcass [4]. Use of growth promoters, such as β-adrenergic agonists (β-AA), may improve growth and carcass characteristics of lambs from hair breeds.…”

Suplementación de clorhidrato de zilpaterol en corderos finalizados con dieta sin fibra de forraje

“…Inesperadamente, los resultados de este estudio mostraron que el origen del sustrato energético usado para la formación de músculo en los corderos suplementados con CZ fue principalmente a partir de tejido adiposo y no de órganos, viseras, cabeza, patas o testículos. Este hallazgo coincide con otras investigaciones en ovinos donde usaron CZ de la empresa Zilmax® (6,18,28) , pero no con esas que suplementaron CZ de la empresa Grofactor® (22,23) como se hizo en este estudio. El CZ de Grofactor® (22,23) promueve en ovinos de engorda la formación de masa muscular por hacer uso de sustratos energéticos provenientes de una mejor repartición de energía dietaria, así como de algunos órganos, viseras o cabeza, pero no a partir de tejido graso.…”

“…El agonista adrenérgico β2 (AA β2) clorhidrato de zilpaterol (CZ) es un promotor de crecimiento que resulta efectivo para mejorar el comportamiento productivo y las características de la canal de importancia económica cuando se ofrece entre 4 y 5 semanas antes del sacrificio a corderos finalizados en corral (3)(4)(5)(6) , no así en pastoreo (7) . Este AA β2 funciona como promotor de crecimiento porque redistribuye sustrato energético del tejido graso y algunos órganos hacia la formación de masa muscular (hipertrofia) (4,8,9) .…”