Effects of feeding yeast (Saccharomyces cerevisiae), organic selenium and chromium mixed on growth performance and carcass traits of hair lambs

Yeasts and organic minerals are used in diets to improve health, productive performance and some carcass characteristics of ruminants and non-ruminants. Thirty-two lambs (Pelibuey×Katahdin; BW=(30.55±1.67) kg; n=8) were used in a 56-d feeding experiment to study the effects of different levels of live yeast (Saccharomyces cerevisiae; yeast), selenium (Se) and chromium (Cr) mixed (Se-Cr), and a mixture of yeast-Se-Cr on growth performance and carcass traits. Animals were stratified by body weight (BW) and randomly assigned to one of four treatments: 1) control group (0.0 g kg−1 yeast); 2) yeast (1.50 g kg−1 dry matter intake (DMI) d−1); 3) Se-Cr premix (1.5 mg kg−1 DMI d−1 for each mineral); and 4) yeast-Se-Cr mixture. There were no treatment effects on final BW; whereas lambs fed Se-Cr or yeast-Se-Cr had higher (P<0.05) DMI than animals supplemented with only yeast. Average daily gain (ADG), gain:feed ratio, chop area, dorsal fat and carcass yield were similar (P>0.05) among treatment groups. In conclusion, supplementation with yeast, Se-Cr mixed or yeast-Se-Cr did not improve ADG, final BW, back fat content and carcass yield of growing of Pelibuey×Katahdin lambs. Supplementation with Se-Cr and yeast-Se-Cr increased DMI, and approximately 250 g ADG animal−1 d−1 was produced with no negative effects on growth and health of the animals.