282 Impact of dietary peroxidized lipids and antioxidant supplementation in feed on growth performance and oxidative status of newly weaned piglets

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.