Dietary CLA supplementation and gender modify fatty acid composition of subcutaneous and intramuscular fat in Iberian × Duroc finishing heavy pigs

The objective of this research was to evaluate the effect of dietary conjugated linoleic acid (CLA) enrichment for finishing heavy fatty pigs on performance, carcass traits and fatty acid composition in subcutaneous and intramuscular fat (IMF), including CLA main isomers concentration. Forty castrated Iberian × Duroc pigs, half males and half females, with 120 (±2.83) kg live weight were used. Pigs were fed experimental diets containing two levels (0 and 1%) of CLA. No effect of CLA was observed on backfat thickness or IMF concentration. In subcutaneous backfat, dietary CLA increased the C16:0, C18:0, c9,t11-CLA , t10,c12-CLA and saturated fatty acids (SFA) proportion and decreased those C18:1 n-9, C18:2 n-6, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) proportions and MUFA/SFA and C18:1 n-9/C18:0 and C16:1 n-7/C16:0 ratios. In the IMF, dietary CLA increased C16:0, SFA, c9,t11 and t10,c12 proportions and reduced C18:1 n-9 and MUFA, MUFA/SFA and C18:1 n-9/C18:0 ratios, but showed no effect on C18:2 n-6 and PUFA proportion. Subcutaneous backfat fatty acid profile was affected by gender, but no gender effect on intramuscular fatty acid profile was observed. CLA isomer accumulation was lower in heavy pigs compared to the lean genotype probably as a consequence of the higher carcass fat concentration in the former.