Effect of vitamin E and porcine stress syndrome (PSS) genotype on antioxidant status and carcass characteristics of pigs

The effects of vitamin E (injected or fed) and porcine stress syndrome genotype on antioxidant status in young pigs and carcass characteristics in market pigs were evaluated. Vitamin E injected pigs had greater serum E than saline injected pigs for 7 d post injection. Homozygous dominant (NN) pigs had lower (P < 0.01) glutathione peroxidase and higher (P < 0.05) CuZn superoxide dismutase activities than Nn 1 d post injection. Vitamin E injection at weaning had no affect on serum E, or enzyme activities measured 28 d later. Serum ceruloplasmin activity in non-injected pigs was lower (P < 0.05) in nn pigs than in NN while the opposite was true in injected pigs. Carcasses of nn pigs were shorter, had less BF, larger LEA, greater kg lean, lower 45 min muscle pH, and were more pale than NN or Nn carcasses (P < 0.05), and nn had greater drip loss (P < 0.05) than NN carcasses regardless of vitamin E injection. When vitamin E was fed, muscle vitamin E was greater (P < 0.01). Carcasses of nn pigs were shorter, paler, had less BF, and greater drip loss (P < 0.05) than NN or Nn. Also, nn had lower 45 min muscle pH, larger LEA and greater kg lean (P < 0.05) than NN carcasses. Nn and nn pigs had altered antioxidant activity and carcass characteristics compared with NN pigs and may have different dietary requirements for nutrients associated with antioxidant capability.