Dietary conjugated linoleic acid is incorporated differentially into tissues of the pig

Conjugated linoleic acids (CLA) have the potential to be incorporated into foods and marketed as functional foods. CLA have anticarcinogenic, antiatherogenic and immune modulating properties as well as the ability to decrease body fat deposition in growing pigs (1). The aim of this study was to determine the total amount of CLA and the rate of assimilation of individual CLA isomers in pig tissue as a result of CLA feeding. Thirty female cross bred (Large White x Landrace) pigs (initial weight 57 kg) were randomly allocated to one of 6 dietary treatments (0, 1.25, 2.5, 5.0, 7.5 and 10.0 g/kg of CLA55 which contains 55% of CLA isomers (Natural Lipids Ltd., Hovdebygda, Norway). The main CLA isomers, tc/ct 11,13; 10,12; 9,11 and 8,10, were present at 18, 30, 25 and 14% (w/w) of the total CLA content, respectively. Pigs were fed ad libitum for 8 weeks and samples of subcutaneous fat (SF) and muscle were collected at slaughter. Total fat was extracted and free acids were analysed using silver-ion high-performance liquid chromatography (2). Transfer efficiencies of the CLA isomers into porcine tissue were calculated as follows: [((final CLA mass – initial CLA mass) – (final CLA mass in control pigs – initial CLA mass in control pigs)) / total CLA consumed] × 100