Effect of age and diet on the fatty acid composition of triglycerides and phospholipids from liver, adipose tissue and crop of the pigeon.

The fatty acid pattern of the triglycerides (TG) and phospholipids (PHL) from liver, adipose tissue and crop of the pigeon was studied at various stages of posthatching development to determine the influence of the changing diet. In each tissue and at all ages PHL contained more steric and polyenoic but less monoenoic acids than the corresponding TG. Especially in the young squabs the acid composition of the liver (TG as well as PHL) was different from that of the adipose tissue and the crop. In these last tissues, only small variations were noticed during growth, whereas in the liver the acid pattern changed drastically and specifically for each lipid fraction, mainly in the 1st week after hatching. During the period of only cropmilk feeding (0-4 days) the TG from adipose tissue and crop resembled more the acid pattern of the diet than that of the liver TG, suggesting that in this period these tissues derive their acids for TG synthesis mostly from exogenous sources rather than from the liver. The subsequent change from cropmilk to grain diet was not clearly reflected in the acid content of the examined tissues probably as a result of an enhanced de novo synthesis. The acid distribution in the PHL of the various tissues was at all ages very different from that of the corresponding diets and their alterations, characteristic for each tissue, may therefore be correlated more with age than with dietary conditions.