The effect of dietary energy and vitamin E administration on performance and intramuscular collagen properties of lambs

The effect of different dietary energy levels, with or without injections of vitamin E, on growth, carcass traits and intramuscular collagen (IMC) characteristics of growing lambs was studied. Twenty-four Ile de France ram lambs were evaluated in a 2 × 2 factorial design involving different DL-α-tocopheryl acetate injections (C, control = 0 and V = 150 IU/wk, i.m. for eight wk) and energy level (N, normal = 7.61 and L, low = 6.47 MJ/kg DM). Growth and slaughter performance, and IMC characteristics were not influenced by diet. DL-α-tocopheryl acetate increased ADG during suckling, while it did not affect live weight, carcass weight and dressing percentage. Vitamin E injections reduced carcass shrinkage but also had a negative effect on pelvic limb percentage. The Longissimus muscle pH values were higher in V than in C lambs. DL-α-tocopheryl acetate reduced IMC maturity and muscle hydroxylysylpyridinoline crosslink concentration, more markedly in lambs fed low energy diets.