RESUMO
The aim of this study was to evaluate the inclusion of different levels of probiotic in the diets of lambs, on ruminal characteristics, intake and digestibility of nutrients. The treatments were 0 (control group), 2, 4 and 6 g/day of probiotic doses, supplied orally and individually to the lambs. Four crossbred Santa Inês X Texel lambs were used, and the experimental design was a Latin square, with four treatments and four periods. Samples of diet, orts, feces, and ruminal fluid were collected from each animal. Intake and apparent digestibility variables were not different (p > 0.05) among the levels of probiotic evaluated. The average daily feed intake of lambs ranged from 1.27 to 1.28 kg of DM/day, and no significant differences (p > 0.05) were obtained between the levels of probiotics used in the diet. The percentage distribution of protozoa was not significant according to the different doses of probiotics used. A positive linear effect was obtained between the pH of the rumen fluid and the probiotic used, indicating that the highest pH values were obtained when the animals received the higher dose of 6 g probiotic; indicative that its use provides a ruminal environment closer to neutrality. The methylene blue reduction test in ruminal fluid samples did not differ between the different doses of probiotics used. The increasing levels of the probiotic in the diet of lambs are related to an increase in ruminal pH, without changing the levels of intake and digestibility of nutrients.