ABSTRACT
The objective of this study was to evaluate the productive performance, apparent digestibility, and carcass and longissimus dorsi muscle characteristics of lambs fed diets supplemented with four levels of Saccharomyces cerevisiae. Thirty-two male Hampshire lambs (25.82±1.95 kg body weight) were distributed in four treatments: basal diet (20:80, forage:concentrate), and the inclusion of 0, 3, 5, and 10 g animal−1 d−1Saccharomyces cerevisiae. The variables evaluated were dry matter intake, daily weight gain, feed conversion, apparent digestibility, dorsal fat thickness, longissimus dorsi muscle area, and physicochemical characteristics of carcass and muscle. We used a completely randomized design and orthogonal polynomials to test the linear and quadratic effects of the inclusion levels of the yeast. Saccharomyces cerevisiae showed a quadratic effect on lamb performance. Dry matter intake decreased with yeast in response to a better feed conversion and body weight gain; however, at the highest Saccharomyces cerevisiae dose, daily weight gain and final weight were lower than with the basal diet treatment. Saccharomyces cerevisiae did not affect apparent digestibility or carcass and muscle physicochemical characteristics. Supplementation with 3 and 5 g d−1 Saccharomyces cerevisiae improves productive performance of lambs fed high concentrate diets without affecting the physicochemical characteristics of the carcass or muscle.
longissimus dorsi; muscle characteristics; sheep; yeast