Dietary fatty acid and carcass lean content. What effect on the quality of backfat ?

Supplying polyunsaturated fatty acids in pig diet affects fatty acid composition and technological properties (consistency, oxidability) of adipose tissues. The aim of this study is to evaluate the consequences of supply of increasing quantities of C18:2 n-6 and C18:3 n-3 on lipid composition (fatty acid, triacylglycerol ) and physical properties (solid fat content, harness) of backfat. 210 pigs from Large White boar were divided into 4 groups according to the PUFA content of diets. Diets 1,2 and 3 contained increasing proportions of C18:2 (from 8.6 to 14.3 g/kg) and diet 2 and 4 contained 1.06 and 1.93 g/kg C18:3.The results show that :Increasing the amount of C18:2 in diet largely affected lipid composition and physical traits of backfat. Its caused an increase in proportions of both PUFA and POL and a decrease in proportions of both saturated and monounsaturated fatty acids and PSO and in both solid fat content and hardness of backfat.C18:2 proportion in backfat can be accurately predicted from the amount of C18:2 in diet, backfat thickness (X4) and the amount of C18:2 in the diet (R2 = 0,76).In the present study, the increase in C18:3 amount in diet (from 1.06 to 1.93) had only a slight effect on lipid composition and physical properties of backfat. Only the proportion of C18:3 was increased.Whatever the diet, backfats were of good quality. French saucissons prepared with the backfats of pigs were judged acceptable by a panel.