|Liu, Pia -|
|Chen, Chi -|
|Weber, Thomas -|
|Johnston, Lee -|
|Shurson, Gerald -|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2014
Publication Date: July 1, 2014
Citation: Liu, P., Kerr, B.J., Chen, C., Weber, T.E., Johnston, L.J., Shurson, G.C. 2014. Influence of thermally-oxidized vegetable oils and animal fats on energy and nutrient digestibility in young pigs. Journal of Animal Science. 92:2980-2986. Interpretive Summary: Energy is one of the most expensive components of swine diets, with lipids being added to livestock diets as concentrated energy source. Depending upon the length and temperature during processing, however, lipids may contain various amounts of peroxidation products which may affect their caloric value to the animal, as well as the digestion of other nutrients in the diet. Data from this experiment suggests that feeding thermally-oxidized lipids to young pigs had little effect on the digestible or metabolizable energy values for any of the lipids tested, and did not appreciably affect total tract digestibility of dietary dry matter, lipid, nitrogen, or carbon. Research results described in this report provides scientists at universities, feed companies, allied industries, and livestock production facilities information that peroxidation of lipids do not appear to affect their caloric value to the animal, and do not affect the digestibility of other nutrients in the diet.
Technical Abstract: A total of 108 barrows (6.67 ± 0.03 kg BW) were assigned to 12 dietary treatments in a 4 × 3 factorial design, plus a corn-soybean meal control diet to evaluate the effect of lipid source and peroxidation level on DE, ME, and apparent total tract digestibility (ATTD) of DM, GE, ether extract (EE), nitrogen (N), and carbon (C) in young pigs. Main effects were lipid source [corn oil (CN), canola oil (CA), poultry fat (PF), and tallow (TL)] and peroxidation level [original lipids (OL), slow oxidation (SO) of lipids heated for 72 h at 95 degrees C, or rapid oxidation (RO) of lipids heated for 7 h at 185 degrees C]. Pigs were provided ad libitum access to diets for 28-d, followed by an 8-d period of controlled feed intake equivalent to 4% BW daily. Diets were formulated based on the ME content of CA with the standardized ileal digestible Lys, Met, Thr, Trp, total Ca, and available P:ME balanced relative to NRC (1998) recommendations. Lipid peroxidation analysis indicated that compared to the OL, SO and RO had a markedly increased concentrations of lipid peroxidation products, and the increase of peroxidation products in CN and CA were higher than those in PF and TL. Addition of lipids to diets increased (P < 0.05) ATTD of EE and tended to improve (P = 0.06) ATTD of GE compared to pigs fed the control diet. Feeding CN or CA increased (P < 0.05) ATTD of DM, GE, EE, N, and C compared to feeding TL, while feeding PF improved (P < 0.05) ATTD of GE and EE, and tended to increase (P = 0.06) ATTD of C compared to TL. Pigs fed CN had increased (P = 0.05) percentage N retention than pigs fed TL. No peroxidation level effect or interaction between lipid source and peroxidation level on DE and ME was observed. Lipid source tended (P = 0.08) to affect DE, but not ME values of experimental lipids (P > 0.12). Digestible energy values for CA (8,846, 8,682, and 8,668 kcal/kg) and CN (8,867, 8,648, and 8,725 kcal/kg) were about 450 kcal/kg higher than that of TL (8,316, 8,168, and 8,296 kcal/kg), with PF being intermediate (8,519, 8,274, and 8,511 kcal/kg) for OL, SO, and RO, respectively. In conclusion, lipid source affected ATTD of dietary DM, GE, EE, N, and C, and N retention rate; and tended to influence the DE value of the lipid, but did not significantly affect their ME value. Rapid and slow heating of lipids used in this study increased lipid peroxidation products, but had minor effects on nutrient and energy digestibility as well as DE and ME values of the various lipids.