|SHURSON, GERALD - University Of Minnesota|
Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2016
Publication Date: 2/1/2017
Citation: Kerr, B.J., Shurson, G.C. 2017. Determination of ether extract digestibility and energy content of specialty lipids with different fatty acid and free fatty acid content, and the effect of lecithin, for nursery pigs. Professional Animal Scientist. 33(1):127-134. doi: org/10.15232/pas.2016-01561.
Interpretive Summary: Many specialty lipid products are highly variable in their fatty acid and free fatty acid concentration due to their origin and processing method. Some of these products are manufactured to be free-flowing and solid at room temperature to facilitate ease of handling, are marketed to achieve specific functional purposes, and may be consist of by-products from the food industry. In addition, some specialty lipid products may be high in free fatty acids which may affect their value as an energy source to young pigs. The experiment was conducted to evaluate the digestible energy content of various specialty lipids in young pigs. Data from this experiment indicate that the apparent total tract digestibility of energy of the specialty lipid products evaluated herein were about half of that observed in commonly fed lipid sources (choice white grease, corn oil, soybean oil) when fed to young pigs. This was most likely due to their high concentrations of saturated fatty acids compared with the lower saturated fatty acid content commonly found in tallow, palm oil, and lard. Furthermore, the addition of lecithin to refined soybean oil or a high free fatty acid soybean oil product did not improve energy digestibility, and the presence of a high free fatty acids in soybean oil had no effect on energy digestibility. This information is important for nutritionists at universities, feed companies, and pig production facilities for the determination of the energy value of various specialty lipids for use in feed formulations, and provides a basis from which to assess its economic value.
Technical Abstract: Various specialty lipids are commercially available and used in nursery pig diets, but may have FA profiles and FFA content that affect their caloric value. In each of 2 experiments, 54 barrows (28-d of age) were fed a common diet for 7-d, allotted to dietary treatments and fed their respective experimental diets for an additional 17-d followed by a 4-d total fecal and urine collection period to determine DE, ME, and ether extract (EE) digestibility of various lipid products or lipid-lecithin combinations. In Exp. 1, 5 sources of specialty lipid products were evaluated. Small differences in DE and apparent total tract digestibility (ATTD) of EE were observed among these products, with the product containing high FFA derived from animal fat having greatest DE, ME, and ATTD of EE (P < 0.05). In Exp. 2, a refined soybean oil (SO) and a SO containing high FFA content (SO-FFA) were fed with or without a de-oiled soybean-based lecithin (LEC). There was an interaction between lipid source and lecithin where LEC decreased DE, DE as a percentage of GE, and ME when included with SO-FFA, but not when added to SO (P < 0.01). When no LEC was added, there was no difference in energy or EE digestibility between SO-FFA and SO. In conclusion, the specialty lipid products evaluated were poorly digested, the addition of LEC to SO or SO-FFA did not improve lipid or energy digestibility, and the presence of high FFA in SO did not negatively affect lipid or energy digestibility.