THE EFFECT OF THE BETA-ADRENERGIC AGONIST CIMATEROL ON PERFORMANCE AND CARCASS AND MEAT QUALITY IN CULLED DAIRY-COWS

Forty-eight culled dairy cows were assigned to one of two treatment gr oups to investigate the effect of a beta-adrenergic agonist in mature cattle. They were finished during a 63-day period on a concentrate die t, containing 0 or 4 mg/kg cimaterol. No food was given in the 20 h pr ior to slaughter. Cimaterol had no effect on food intake, but signific antly improved food conversion efficiency and increased live-weight ga in, carcass weight and dressing proportion (P<0.05). Cimaterol induced muscle hypertrophy as evidenced by an improved EUROP carcass classifi cation 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-valu e 37.0 v, 35.6; P<0.05) with a higher shear force value (64.0 b. 46.4 Newton; P<0.01) compared with control animals. It seems likely that ma ture cattle receiving cimaterol respond similarly to younger growing a nimals.