[Triglyceride fatty acids of abdominal adipose tissue in two lines of chickens rendered lean or fat by selection].

Newly-hatched chickens from two lines selected for high or low abdominal fat/live weight ratio, were fed on a stock low-lipid diet (2.9 wt % lipids) for nine weeks. Linoleic acid made up 54.3% of dietary fatty acids. Their abdominal adipose tissue and liver triglycerides were then isolated for fatty acid analysis. The linoleic acid content of abdominal fat triglycerides was higher in lean than in fat chickens (19.2 vs 16.4% of triglyceride fatty acids, respectively). This difference was highly significant. Conversely, the level of monounsaturated fatty acids in the abdominal fat triglycerides was significantly lower (especially palmitoleic acid) in lean than in fat chickens. The proportion of linoleic acid in liver triglycerides was also higher in lean than in fat chickens (12.2 vs 5.5% of triglyceride fatty acids). The higher dilution of dietary linoleic acid within the depot fat of the fat line chickens shows that the flux of endogenous fatty acids from the liver was larger in these animals than in the lean ones. Moreover, the elevated amounts of palmitoleic acid (virtually absent from the diet) in the depot and liver triglycerides of fat chickens, was most likely caused by a higher delta 9-desaturating activity in the liver of the latter animals.