Meat Quality in Katahdin Lamb Terminal Crosses Treated with Zilpaterol Hydrochloride

The effect of Zilpaterol hydrochloride (ZH) supplementation (0 vs. 0.15 mg/kg live weight) on the meat quality was evaluated in Katahdin x Charollais (32 KCh) and Katahdin x Dorper (28 KD) crosses. Lambs were fed a totally mixed ration with 14% crude protein (CP) and 2.9 Mcal EM/kg DM. Data were analyzed using a completely randomized 2 x 2 factorial design: 2 genotypes (KCh and KD) and 2 ZH levels (0 and 0.15 mg/kg live weight). No interaction was found between ZH and the genotypes. The breed of the sire (BS) did not affect most of the meat traits, only KCh crosses had higher color values (L* = 34.0±0.6 vs. 35.6±0.6; a* = 13.4±0.3 vs. 14.9±0.4; b* = 5.6±0.3 vs. 6.6±0.4; h* = 20.8±0.9 vs. 23.0±0.09; C* = 14.7±0.4 vs. 16.4±0.5), more fat (11.2±0.5 vs. 11.9±0.5) and less protein (21.3±0.1 vs. 21.8±0.0) than KD. ZH meat had lower values (P < 0.001) than meat from the control animals: L* (31.9±0.6 vs. 37.7±0.6), a* (12.9±0.4 vs. 15.5±0.4), h* (15.1±0.9 vs. 28.6±0.9) and C* (13.5±0.5 vs. 17.7±0.8). ZH increased shear force on meat (5.4±0.2 vs. 3.7±0.2 kgf), and produced less fat (9.7±0.5 vs. 12.5±0.5%) and bone (23.2±0.3 vs. 24.6±0.2%), but more muscle (65.8±0.5 vs. 61.2±0.4%). Zilpaterol hydrochloride use in lamb production caused leaner yield and more protein retention, at the expense of reducing meat sensory qualities.