Zilpaterol hydrochloride improves growth performance and carcass traits without affecting wholesale cut yields of hair sheep finished in feedlot

• Published in: Journal of Applied Animal Research Vol. 46; no. 1; pp. 375 - 379
• Main Authors: Rojo-Rubio, Rolando, Avendaño-Reyes, Leonel, Albarrán, Benito, Vázquez, José F., Soto-Navarro, Sergio A., Guerra, Juan E., Macías-Cruz, Ulises
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01-01-2018; Taylor & Francis Group
• Subjects: carcass; Ram sheep; wholesale cuts; β2-adrenergic agonists
• ISSN: 0971-2119; 0974-1844
• DOI: 10.1080/09712119.2017.1307756

Fourteen Dorper × Pelibuey ram lambs (initial body weight [BW] = 37.4 ± 1.0 kg and age = 4.5 mo) were housed in individual pens during a 30-d feeding period, and then slaughtered to determine the effects of zilpaterol hydrochloride (ZH) supplementation on productive performance, carcass characteristics and wholesale cut yields. Lambs were assigned under a randomized complete block design (initial BW as blocking factor) to one of two dietary treatments: basal diet without (control) or with 10 mg daily of ZH/lamb. Lambs fed ZH had greater (P ≤ .04) final BW, average daily gain and dry matter intake, but similar (P = .24) feed efficiency compared with control lambs. Hot and cold carcass weight, dressing percentage, longissimus muscle area and leg perimeter were greater (P ≤ .05) for ZH-fed lambs than for control lambs. With exception of blood percentage which decreased (P < .01) with ZH, wholesale cut yields and non-carcass components were unaffected (P ≥ .12) by ZH supplementation. In conclusion, ZH can be used to improve growth rate and dressing percentage, but not to increase wholesale cut yields in feedlot finishing ram lambs.