Effects of organic chromium supplementation to finishing lambs diet on growth performance, carcass characteristics and meat quality

The objective of this study was to evaluate supplemental organic chromium (Cr) to finishing lambs on growth performance, carcass characteristics, and meat quality. Eighteen Suffolk lambs (age (4.5±0.2) mon; (25.8±3.6) kg body weight (BW)) were randomly assigned to three levels of supplemental organic Cr (0.0, 0.2 and 0.4 mg kg−1 dry matter (DM)) in a complete random design. Growth performance was evaluated for 70 d, and then lambs were slaughtered to study carcass characteristics and chemical composition of meat. Orthogonal contrasts were performed (contrast one-average level 0.2 ppm Cr vs. average level 0.4 ppm Cr; contrast two-level 0 vs. average levels (0.2+0.4) ppm Cr). Orthogonal polynomials were used to estimate the linear and quadratic effects of Cr concentrations. Growth and carcass performance were not affected by supplemental organic Cr. Muscle conformation and leg perimeter linearly increased (P<0.05) as organic Cr level increased in the diet. Kidney fat decreased linearly (P<0.05) as supplemental Cr increased. In Longissimus dorsi (LD), the ash content decreased linearly, and shear force (kg cm−2) increased (P<0.05) as organic Cr level increased in the diet. It is concluded that organic Cr did not affect growth performance, but it improved positively the muscle conformation, reduced kidney fat, whereas in LD there was an increment in shear force in finishing carcass lambs.