Effect of yeast culture combined with sodium monensin on the productivity and health of feedlot cattle

The inclusion of ionophores and/or natural additives in animal feed, supplied alone or in combination, can bring benefits during the productive periods of beef cattle production. The experiment was conducted was to evaluate the productive performance, ingestive behavior, apparent digestibility of the concentrate, and carcass traits of steers finished in confinement receiving yeast culture (Saccharomyces cerevisiae) combined or not with sodium monensin in the diet: MON-diet with sodium monensin (250 mg animal day-1); CUL-diet with yeast culture (7 g animal day-1); and MON + CUL-diet with yeast culture and sodium monensin (7 g animal day-1 + 250 mg animal day-1). Thirty-six whole steers, 1/2 Angus Nellore, with an average initial bodyweight of 416 kg, were used in the experiment. Steers fed yeast culture showed higher values for average weight gain (1.6144 kg day-1), improvements in carcass finishing, better capacity to convert ingested DM into carcass gain (9.34 day-1), apparent digestibility of DM (72.37%) and NDF (48.28%) compared to animals on sodium monensin. The combination demonstrated intermediate values for DMI (10.10 kg day-1), hindquarter fat thickness (6.67 mm), and rump fat thickness (5.24 mm). Sodium monensin resulted in intermediate values for DMD (71.73%), and forequarter fat thickness (3.58 mm). Using yeast culture promoted greater average weight gain, better carcass finishing, and better capacity to transform ingested DM into carcass gain, because of improvements in the apparent digestibility of DM and NDF compared to the diet with sodium monensin.