Abstract
The objective of this study was to evaluate the use of dietary vitamin E (VitE) and polyphenols on growth and oxidative status of weaned piglets fed peroxidized lipids. Pigs (n = 192; 21-d of age; 6.62±1.04 kg BW) were assigned within sex and weight blocks to a 2x3 factorial arrangement using 48 pens (4 pigs/pen; 8 replications/treatment). Factors consisted of lipid peroxidation (6% human-grade soybean oil or 6% peroxidized soybean oil), and antioxidant supplementation (control diet containing 25 IU/kg dl-α-tocopherol-acetate; control with 200 IU/kg additional dl-α-tocopherol-acetate; or control with 400 mg/kg polyphenols). Peroxidation was accomplished by heating control oil at 80°C with constant air flow at 50 L/min for 12 d (initial peroxide, anisidine value, hexanal, and 2,4-decadienal concentrations were 4.1 vs. 141.6 meq/kg, 1.7 vs. 106, < 5 vs. 99 mg/kg, and 8 vs. 720 mg/kg for control and peroxidized oil, respectively). Diets were fed in 2 phases (14 and 21 days). Overall, peroxidized lipids decreased (P < 0.001) BW (23.16 vs. 18.74 kg), ADG (473 vs. 346 g/day), ADFI (658 vs. 535 g/day) and G:F (719 vs. 647 g/kg). Lipid peroxidation decreased serum vitamin E (P < 0.001) and this decrease was larger on d35 (1.82 vs. 0.81 mg/kg) than d14 (1.95 vs. 1.38 mg/kg). Supplemental VitE, but not polyphenols, increased (P < 0.002) serum vitamin E by 84 and 22%, for control and peroxidized diets, respectively (interaction, P = 0.001). Serum malondialdehyde decreased (P < 0.001) with peroxidation on d14, but not d35 and protein carbonyl increased (P < 0.001) with peroxidation on d35, but not d14. Serum 8-hydroxydeoxyguanosine was not affected (P > 0.05). Total antioxidant capacity decreased with peroxidation (P < 0.001) and increased with VitE (P = 0.065) and polyphenols (P = 0.046) in the control oil diet only. Peroxidized lipids reduced growth performance, which could not be corrected with supplemental vitamin E or polyphenols in the diet.