Growth performance and carcass composition of broilers fed supplemental chromium from chromium yeast

Three experiments were conducted to evaluate the effects of chromium (Cr) from Cr yeast (1 g kg−1) on the growth and carcass composition of growing broilers. The birds were fed corn soybean meal diets containing a basal level of 650–710 μg kg−1 Cr. The diet was supplemented with Cr at a level of 0, 300, 600 μg kg−1 (Trial 1); 0 and 400 μg kg−1 (Trial 2) and 0, 150 and 300 μg kg−1 (Trial 3). Supplementation with Cr did not affect (P≥0.05) body weight, feed consumption or feed:gain ratio of broilers during days 1–21 in trial 1 which was conducted in battery brooders. Male broilers reared in floor pens (Trial 3) during days 1–21 had significantly (P≤0.01) higher feed consumption with 300 μg kg−1 Cr in the diet, but the feed:gain ratio between the treatments was unaffected. Body weight of mixed sex broilers from days 28–47 was not influenced, but feed:gain ratio and mortality were significantly (P≤0.05) reduced with 400 μg kg−1 of Cr in the diet in Trial 2. Broilers reared in floor pens with supplemental Cr at a level of 300 μg kg−1 had significantly (P≤0.05) higher body weight at 42 days in Trial 3. Feed consumption was significantly increased and feed:gain ratio was improved (P≤0.05) with 300 μg kg−1 of supplementary Cr in the diet. Mortality of broilers was reduced, and breast meat yield improved (P≤0.05) with supplemental Cr at either 300 or 400 μg kg−1. Carcass weight was increased and abdominal fat pad as a percent of carcass weight was reduced significantly (P≤0.05) with 300 μg kg−1 supplemental Cr in the diet.