Effects of supplemental phytomolecules on growth performance, carcass characteristics and liver abnormalities of finishing beef steers

This study was conducted to evaluate the growth performance and carcass characteristics of finishing steers fed diets containing different feed additives: control (CTL; no feed additives); monensin [26 mg/kg dry matter (DM); MON]; a blend of cinnamaldehyde, eugenol, and capsicum (120 mg of a commercial product/kg DM; XT), or the combination of monensin and the blend of cinnamaldehyde, eugenol, and capsicum (26 mg/kg DM and 120 mg of a commercial product/kg DM, respectively; MON + XT). A total of 860 steers [initial body weight (BW) = 334 kg] were fed the basal diet (7% alfalfa hay and 93% concentrate; DM basis) containing the treatments during 154 days. Feed additives did not affect final BW, DM intake, average daily gain, and feed efficiency of finishing steers (P >= 0.12). Dressing percentage was lower for MON + XT than MON and XT (P = 0.01). Feeding XT tended to increase the percentage of the carcass with a small marbling score compared to MON (P = 0.09). The proportion of carcass grading premium choice tended to be greater for steers fed MON compared to XT (P = 0.07). The feed additives evaluated herein did not affect the growth performance of finishing beef steers and had little effects on carcass characteristics.