NÍVEIS PLASMÁTICOS E EXCREÇÃO DE URINA DE METABÓLITOS DE URÉIA E CREATININA DE ANIMAIS ALIMENTADOS COM MILHO EM GRÃO

The aim of this study was to evaluate the plasma concentration and excretion of urea and creatinine from grazing cattle and supplemented with corn grain and to identify the best level of Saccharomyces cerevisiae yeast as a possible modulator of ruminal fermentation. Five cannulated animals were used, treatments were 5 levels of yeast in the diet (0 CFU (colony forming unit), 100 CFU x109, 200 CFU x109, 300 CFU x109, 400 CFU x109) of the animals. The data were submitted to analysis of variance and polynomial regression, determining the linear and quadratic effects, where the yeast levels were considered the treatments and the significance was established at P <0.05. No statistical difference in results found at different levels. The inclusion of yeasts in maize supplementation of grazing cattle did not alter the plasma concentrations and urea and creatinine excretion of the animals.