RESUMEN

To assess the effects of dietary CLA, lysine and sex on performance, blood metabolites, carcass characteristics, meat quality and skeletal development, seventy-two pigs (initially 105.3±6.6kg live weight) barrows and gilts, were assigned to one of four diets in a 2×2×2 factorial arrangement. The diets contained 0% or 0.75% CLA, and 0% or 0.16% of l-lysine-HCl. All pigs were slaughtered at an average weight of 153.4±11.0kg. Neither CLA nor lysine supplementation influenced growth, blood metabolites or carcass characteristics. CLA reduced (P<0.05) pH(24) and increased (P<0.01) yellowness (b(∗)) of the Longissimus muscle. Lysine increased (P<0.01) pH(24) and reduced (P<0.01) muscle ash content. CLA reduced (P<0.05) collagen synthesis, and lysine increased (P<0.05) collagen synthesis in Longissimus muscle, but no influence on intramuscular collagen maturity or muscle hydroxylysylpyridinoline crosslink concentration were observed. In addition, metacarpal bone diameter was reduced (P<0.05) by CLA. Barrows had higher ADG, final weight (P<0.01), carcass weight, lean percentage (P<0.05), serum cholesterol (P<0.05) and triacylglycerol (P<0.001) than gilts. Metatarsal diameter was larger in gilts than barrows (P<0.05).