Published online by Cambridge University Press: 02 September 2010
Forty-eight culled dairy cows were assigned to one of two treatment groups to investigate the effect of a β-adrenergic agonist in mature cattle. They were finished during a 63-day period on a concentrate diet, containing 0 or 4 mg/kg cimaterol. No food was given in the 20 h prior to slaughter.
Cimaterol had no effect on food intake, but significantly improved food conversion efficiency and increased live-weight gain, carcass weight and dressing proportion (P < 0·05). Cimaterol induced muscle hypertrophy as evidenced by an improved EUROP carcass classification and a higher longissimus thoracis (LT) cross-sectional area (P < 0·001). EUROP fat score and fat content in the carcass and the LT were lowered (P < 0·05). Cimaterol resulted in brighter meat (higher L-value: 37·0 v. 35·6; P<0·05) with a higher shear force value (64·0 v. 46·4 Newton; P<0·01) compared with control animals. It seems likely that mature cattle receiving cimaterol respond similarly to younger growing animals.