Leveduras e enzimas fibrolíticas na dieta de cordeiros: consumo, digestibilidade e balanço de nitrogênio

Abstract

The objective this experiment was evaluating the effect of the additives inclusion (yeast and fibrolytic enzyme) in the diet for lambs on consumption, nutrient digestibility and nitrogen balance. The base diet was composed of milled corn, soybean meal, chopped tifton-85 hay and premix mineral in the proportion of bulky concentrate of 40:60. The diets in relation to the treatments were followed by (1) base diet without addition of additives, (2) base diet added with 100% enzyme, (3) base diet with 70% enzyme association and 30% yeast (4) base diet with 100% yeast and (5) base diet with 30% enzyme and 70% yeast. Twenty-five whole male lambs with a mean weight of 25 kg and a standard deviation of 1.23% were used, distributed in a completely randomized design in the metabolic cages in a 21-day experiment (14 days of adaptation to the diets and facilities and 7 days of collection of samples). With the use of isolated or associated additives, no significant effects (p≥0.05) on dry matter intake, crude protein, ethereal extract, protein corrected neutral detergent fiber, non-fibrous carbohydrates and total nutrients were observed. With the inclusion of the additives in the diet did not present significant difference on the digestibility of all nutritional fractions (p≥0.05). In this study it was possible to observe a numerical increase of urinary nitrogen (p≤0.05) with the inclusion of total yeasts, but in general, the additives showed no difference in the nitrogen balance. The results obtained with the experiment showed the additives supplemented to diets may have a minimal effect on the studied parameters.