Location: Agroecosystems Management ResearchTitle: Influence of thermally-oxidized vegetable oils and animal fats on growth performance, liver gene expression, and liver and serum cholesterol and triglycerides in young pigs Author
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2014
Publication Date: 7/1/2014
Publication URL: http://handle.nal.usda.gov/10113/59412
Citation: Liu, P., Chen, C., Kerr, B.J., Weber, T.E., Johnston, L.J., Shurson, G.C. 2014. Influence of thermally-oxidized vegetable oils and animal fats on growth performance, liver gene expression, and liver and serum cholesterol and triglycerides in young pigs. Journal of Animal Science. 92:2960-2970. Interpretive Summary: Lipids are commonly added into swine diets as concentrated energy sources to improve feed efficiency, reduce dust, supply fat soluble vitamins and essential fatty acids, and improve diet palatability. Lipids obtained from food processing or rendering facilities have been heated for a considerable length of time and may therefore contain various amounts of peroxidation products which has been shown to affect animal growth and lipid metabolism in rodents. Data from this experiment suggests that feeding thermally-oxidized lipids to young pigs may reduce growth performance, decrease liver triglyceride concentrations, and alter the expression of various genes, especially in lipids containing high concentration of polyunsaturated fatty acids. Research results described in this report provides scientists at universities, feed companies, allied industries, and livestock production facilities information that peroxidized lipids can affect pig performance and lipid metabolism, and therefore the state of lipid peroxidation needs to be considered in the use of lipids as an animal feed ingredient.
Technical Abstract: To evaluate the effect of feeding thermally-oxidized vegetable oils and animal fats on growth performance, liver gene expression, and liver and serum fatty acid and cholesterol concentration in young pigs, 102 barrows (6.67 ± 0.03 kg BW) were divided into 3 groups and randomly assigned to dietary treatments in a 4 × 3 factorial arrangement. The main factors were lipid source [n = 4: corn oil (CN), canola oil (CA), poultry fat (PF), and tallow (TL)] and lipid peroxidation level [n =3: original lipids (OL), slow oxidation (SO) through heating at 95 degrees C for 72 h, or rapid oxidation (RO) through heating at 185 degrees C for 7 h]. Pigs were provided ad libitum access to diets in group pens for 28 d, followed by controlled feed intake in metabolism crates for 10 d. On d 39, all pigs were euthanized for liver samples to determine liver weight, lipid profile, and gene express patterns. Lipid oxidation analysis indicated that compared to the OL, SO and RO had a markedly increased concentrations of primary and secondary peroxidation products, and the increased lipid peroxidation products in CN and CA were higher than those in PF and TL. After a 28-d ad libitum feeding period, pigs fed RO tended to have reduced ADFI (P = 0.09), and ADG (P < 0.05) compared to pigs fed OL, and pigs fed CA had reduced G:F (P < 0.05) compared to pigs fed all other lipids. Pigs fed RO lipids tended to have increased liver weight (P = 0.09) compared to pigs fed OL. Liver triglyceride concentration (LTG) in pigs fed OL was greater (P < 0.05) than in pigs fed RO, and tended to be greater (P < 0.07) than in pigs fed SO. The reduced LTG were consistent with increased (P < 0.05) mRNA expression of PPARa factor target genes (acyl-CoA oxidase, carnitine palmitoyltransferase-1, and mitochondrial 3-hydroxy-3-methylglutary-CoA synthase) in pigs fed SO and RO lipids compared with pigs fed OL. Pigs fed CN or CA tended to have increased LTG (P = 0.09) compared to pigs fed TL. Liver cholesterol concentration in pigs fed CN was less (P < 0.05) than pigs fed PF, and tended to be less (P = 0.06) than pigs fed TL, whereas pigs fed CA had a reduced (P < 0.05) liver cholesterol compared to pigs fed PF or TL. In conclusion, feeding thermally-oxidized lipids negatively affected growth performance and liver triglyceride concentrations of young pigs.