Prediction of the fatty acid composition in backfat of pigs as breeding tool

Pork fat is a major constituent of many meat products and its quality therefore of high relevance for meat processors. The most important fat quality characteristics - oxidative stability and consistency - are well described by the amount of polyunsaturated fatty acids (PUFA) and the iodine value. In Switzerland, these two traits are even part of the payment system for pig carcasses. The amount of PUFA and the iodine value are not only influenced by the lipid composition of the feed, but also depend on genetic factors. In order to include fat quality traits as selection criteria in the pig breeding program, a rapid method using near-infrared spectroscopy was developed at the pig performance testing station MLP at Sempach. This method allows for a rapid determination of the fat quality traits saturated, monounsaturated and polyunsaturated fatty acids (SFA, MUFA, PUFA), iodine value, fat and water content in the backfat of individual pigs. In this way, the fat quality of nearly 2000 fattening pigs was recorded at MLP. Based on this dataset, medium to high heritabilities were estimated for the fat quality traits, indicating a high potential for modifying the fatty acid composition of pig adipose tissue by means of breeding. Breeding for a lower amount of PUFA - as requested by meat processors - will also reduce "empty fat tissue" (high water content) due to the positive genetic correlation. The unfavorable relation between PUFA and loin muscle thickness (0.3) is less strong than the relation between PUFA and lean meat content (0.61). Therefore, the current breeding efforts to increase lean meat content by means of increasing muscle thickness rather than reducing backfat thickness will positively affect the fat quality as well.