Influence of dietary rapeseed oil, vitamin E, and copper on the performance and the antioxidative and oxidative status of pigs

We investigated the effects of dietary copper and vitamin E in diets contai ning 6% rapeseed oil on the performance and the antioxidative and oxidative status of growing pigs. The 10 dietary treatments consisted of a basal die t (9 mg of vitamin E/kg feed, 15 mg of Cu/kg feed),the basal diet + 6% rape seed oil (Diet 1; 18 mg of vitamin E/kg feed, 15 mg of Cu/kg feed), and Die t 1 plus supplements of vitamin E (0, 100, and 200 mg of dl-alpha-tocophery l acetate/kg feed) and copper (0, 35, and 175 mg of Cu/kg feed) in a 3 x 3 factorial arrangement of treatments. Eight or nine pigs were given ad libit um access to each diet from 25 to 100 kg of live weight. The inclusion of r apeseed oil tended (P < .10) to improve ADG and feed utilization. Compared with the addition of 35 mg of Cu/kg, the addition of 175 mg/kg improved gro wth rate and increased feed intake early in the experiment, but, over the t otal experiment, neither 35 nor 175 mg Of Cu/kg affected performance. Compa red with the addition of 100 mg of vitamin E/kg or no addition, the additio n of 200 mg/kg reduce ADG over the total experiment (P = .05). The antioxid ative and oxidative status of the pigs was evaluated in terms of blood and liver concentrations of antioxidants (alpha-tocopherol, ascorbic acid, vita min A, superoxide dismutase, glutathione peroxidase), prooxidants (Gu), con centrations of lipids (triglycerides and cholesterol), fatty acid compositi on, thiobarbituric acid-reactive substances (TBARS), and clinical chemical (creatine kinase and glutamate-oxaloacetate-transaminase) and hematological variables that indicate the level of oxidative stress,There were no vitami n E deficiency signs or increased oxidative stress in pigs fed low dietary vitamin E levels, and no prooxidative effect of Cu was found. Increasing di etary levels of vitamin E increased the concentration of alpha-tocopherol i n plasma and liver. Supplementation with Cu increased liver concentrations of Cu and alpha-tocopherol. The progression in liver TEARS was reduced by t he addition of vitamin E and Cu. The addition of rapeseed oil changed the f atty acid composition of liver, increased a-tocopherol concentration in pla sma and Cu concentration in liver, and reduced the rate of lipid oxidation in liver. In conclusion, even though the effects were minor, vitamin E, Cu, and rapeseed oil improved the antioxidative status of the live pigs.