Abstract
The study objective was to assess the contribution of fat source and vitamin E (VE) supplementation on growth performance, antioxidant status, and fatty acid profile in the liver of pigs at heavy slaughter weight (148.09 ±1.64 kg). A total of 72 individually-fed pigs (36 barrows, 36 gilts; 28.55 ±1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments were tallow and corn-oil. The VE treatments included four levels of α-tocopheryl-acetate (ATA; 11, 40, 100, and 200 ppm) and two levels of mixed tocopherols (primarily γ-tocopherol; 40 and 100 ppm). Liver samples were collected at slaughter. Data analysis were performed by ANOVA using GLM in SAS. No effect of dietary fat sources, isoforms of VE, and levels of γ-tocopherol were detected on growth performance or liver antioxidant status (GSH, GSSG, SOD, and MDA). Increasing dietary ATA linearly increased overall ADG (0.98, 1.02, 1.02, and 1.08 kg/day; P = 0.02) from 28 to 150 kg; overall ADG of pigs fed γ-tocopherol-diets was 1.07 and 1.04 kg/day, respectively. An interaction between fat sources and ATA was observed on cumulative ADG during Phase1-3 (28-100 kg; P = 0.04) and Phase1-4 (28-125 kg; P = 0.03) wherein pigs fed corn-oil-diet, but not tallow-diet, had increased ADG with increased dietary ATA. Increasing dietary ATA quadratically increased SOD activity (P < 0.05; highest at 100 ppm), and quadratically decreased MDA content (P < 0.05; lowest at 40 ppm) in the liver. Liver fatty acid profile was affected by fat source (P < 0.05) but not VE treatment, pigs fed corn-oil-diets had less SFA (34.23 vs. 35.45%; P = 0.02) and MUFA (11.98 vs. 18.38%; P < 0.0001), but more PUFA (49.14 vs. 40.78%; P < 0.0001) than pigs fed tallow-diets in the liver. Beneficial effects of dietary VE supplementation were observed on growth performance and antioxidant status of pigs under conditions of this study.
193 Growth performance of lambs and kids on pasture
