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 (P0.05) 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.