Effects of Supplementing with Soybean Oil and Finishing with Beef Tallow on Pork Quality and Carcass Composition

Purdue University 1999 Swine Research Report. Carcass quality reflects the physical and chemical properties of both fat and lean, and these are affected by a number of factors including diet and genetics. We hypothesize that an optimal fatty acid profile in animal fat is required to assure consistent quality of products, and that variability in the quality of dietary fats and genetic differences in tolerance to dietary fat leads to inconsistency in carcass quality. In this trial, soybean oil (SBO) was fed to two divergent genotypes of gilts in an effort to enrich their fat with 18:2 (n-6) and 18:3 (n-3) poly-unsaturated fatty acids. These fatty acids are believed to negatively influence fat firmness when found in high concentrations, and do naturally occur in pig fat at such levels. Following removal of SBO, changes in the concentration of these fatty acids, coupled with changes in adipose cell volume, will allow us to calculate the rate of depletion of fatty acids from adipose cells. Similarly, the rate of fatty acid accretion into adipose triglycerides can be calculated by supplementing with beef tallow, a highly saturated fat. Estimates of these rates, and knowledge of how genotype influences synthesis and breakdown rates, will provide valuable information for the development of feeding strategies that will ensure a desired fatty acid composition endpoint.