Effect of increasing amounts of a linoleic-rich dietary fat on the fat composition of four pig breeds. Part II: Fatty acid composition in muscle and fat tissues

This paper studies the change of fatty acid profile in four different tissues of the pig (backfat, abdominal fat, and the muscles trapezius and longissimus thoracis et lumborum) in response to four diets containing increasing amounts (0%, 2%, 4% and 8%) of a high linoleic acid fat blend, in a sample of 48 pigs of four different breeds (Landrace, Large White, Duroc and a crossbreed Landrace × Duroc). The effects of dietary fat and breed on this profile have been separately tested for each tissue. The diet effect (increasing % of linoleic acid intake) was positive on linoleic acid deposit in all tissues, meanwhile it was negative on palmitic and stearic levels, as well as for the oleic acid. However, this effect was clear in the four tissues for the linoleic acid, while the differences did not follow the same pattern for the saturated fatty acids in trapezius muscle and abdominal fat. Although the levels of arachidonic acid in muscle tissues were higher than those found in adipose tissues, the increasing effect of the diet was stronger, in relative terms, in adipose tissues. The breed effect was, in general, lower than the diet effect. Landrace showed the higher ability to increase linoleic acid levels, particularly in the loin (longissimus thoracis et lumborum), whereas Duroc pigs seemed to be the most resistant to change of fatty acid composition according to the diet.