Effects of dietary chromium-yeast level on growth performance, blood metabolites, meat traits and muscle fatty acids profile, and microminerals content in liver and bone of lambs

To assess the effect of dietary supplement levels of chromium-yeast (Cr-yeast) on growth performance, blood glucose and triglycerides, fatty acid (FA) profile in intramuscular fat, carcase and meat traits, iron, copper, chromium and zinc concentrations in liver and bone, 24 Rambouillet male lambs (29.2 +/- 0.17 kg body weight) were randomly assigned to four diets with 0, 0.2, 0.4 and 0.6 mg Cr/kg DM. The growth performance trial lasted 49 d. Supplemental Cr-yeast did not affect growth performance and carcase characteristics (p > .05), but reduced (p < .05) perirenal and intramuscular fat, as well as 3 h post-feeding blood glucose and triglycerides concentration. In liver, Fe and Cu concentration decreased (p < .05), while Cr concentrations in liver increased with increasing Cr-yeast dietary levels. In bone, Fe decreased (p < .05) as Cr-yeast dietary levels increasing, and Cr-yeast supplementation increased Cr concentrations (p < .05). As Cr-yeast dietary level increased, palmitic (C16:0) and stearic (C18:0) SFA decreased linearly (p < .05), while palmitoleic (C16:1n-7), vaccenic (C18:1n-7), linoleic (C18:2n-6) and arachidic (C20:4) unsaturated fatty acids (UFA) increased linearly (p < .01). In conclusion, Cr-yeast did not affect growth performance and carcase quality, but decreased the perirenal and intramuscular fat, blood glucose and triglyceride content, and Fe and Cu concentrations in liver as increased Cr-yeast levels in the diet. Because supplemental Cr-yeast improved index of atherogenicity and unsaturated to saturated FA ratio in muscle of lambs, it could be of human nutritional interest.