Meat Quality, Digestibility and Deposition of Fatty Acids in Growing-finishing Pigs Fed Restricted, Iso-energetic Amounts of Diets Containing either Beef Tallow or Sunflower Oil

The influence of dietary beef tallow (BT) versus sunflower oil (SO) on meat quality and apparent digestibility and deposition of individual fatty acids in the whole carcass was investigated in pigs fed diets containing either BT or SO. The diets contained equal amounts of energy in the form of the variable fats and were fed on an iso-energetic, restricted basis. Crude fat in the SO diet was better digested (p<0.001) than in the BT diet. The dietary fat type had no effect on growth performance, physical properties of the carcass and meat quality. The pigs fed the BT diet showed lower (p<0.001) apparent digestibilities for palmitic and linoleic acid, but those of oleic and ${\alpha}$-linolenic acid were not affected. The ratio of deposition in the carcass to intake of digestible fatty acids for the whole feeding period was decreased (p<0.01) for oleic and linoleic acid in pigs fed the SO diet. The pigs fed the SO diet instead of the BT diet had a lower (p<0.05) deposition:intake ratio for mono-unsaturated fatty acids. The calculated minimum de novo synthesis of saturated fatty acids was increased for the SO diet, but that of mono-unsaturated fatty acids was not different. In conclusion, the iso-energetic replacement of BT by SO had a marked impact on the fatty acid composition of tissues, but did not affect carcass and meat quality traits in spite of the marked difference in the deposition of linoleic acid in adipose tissues, loin muscle and the whole body. In addition, it became clear that the type of dietary fat had marked, specific effects on the synthesis and oxidation of fatty acids.