The objective of this experiment was to evaluate the performance, carcass and meat characteristics of non-castrated cattle with or without monensin (M) and/or probiotic (P) (Saccharomyces cerevisiae) to the diet. The animals were divided into individual stalls, being left 145 days in feedlot. The roughage used was corn silage + 1.2% of the weight live of concentrate in natural matter basis. There was no effect of the addition of the addictives supplied isolated or associated over feed intake, weight gain and fed conversion. Feed intake, weight gain and feed conversion averages presented quadratic behavior with the increase of the period feedlot. Although the addition of M or P to the diet resulted in the numeric increase (P>.05) of the intake (4.2%) the average of weight gain reduced (5.8 and 5.3%, respectively), resulting in smaller fed conversion (P>.05). The association of M+P already increased (P>.05) the food intake to the order of 9.5% with concomitant increase (P>.05) of the weight gain (6,4%) when compared to diet control. The animals fed with M+P presented better carcass finish (5.5mm), followed by the control (4.7mm), and smaller values, it was verified in the carcasses of the animals that received M (3.7mm) and P (3.5mm). The addition of monensin and/or probiotic for feedlot steers did not improve the performance, carcass and meat quality.
beef cattle; fat thickness; feedlot; ionofore; Sacharomyces cerevisiae
