THE RELATIONSHIP BETWEEN THE FATTY-ACID PROFILES OF THE YOLK AND THE EMBRYONIC TISSUE-LIPIDS - A COMPARISON BETWEEN THE LESSER BLACK-BACKEDGULL (LARUS-FUSCUS) AND THE PHEASANT (PHASIANUS-COLCHICUS)

Although substantial information is available regarding the fatty acid composition of lipids of the yolk and of the developing tissues of th e chicken embryo, there is little knowledge on this topic for other av ian species. The aim of the present study was to compare the yolk and embryonic tissue fatty acid profiles for a species selecting its food in the wild (the lesser black backed gull) with one fed on a standard commercial diet (the commercially reared pheasant). The fatty acid com positions of the yolk lipids were determined, and major differences we re observed between the two species. In particular, the phospholipid o f the gull yolk was enriched in 20:4n-6 and 22:6n-3 (18.8 and 7.1%, re spectively, by weight of total fatty acids) in comparison with the phe asant (4.0 and 4.1%, respectively). The fatty acid compositions of the embryonic tissues were determined using eggs incubated in the laborat ory. For the liver and heart, the fatty acid composition of the lipids in the two species reflected the initial yolk composition, with the g ull tissue lipids generally containing higher proportions of 20:4n-6 a nd 22:6n-3 than those of the pheasant. In contrast, the fatty acid pro files of the brain phospholipid were essentially identical in the two species, with 20:4n 6 and 22:6n-3 comprising approximately 9 and 17%, respectively, of total fatty acids in both cases. Copyright (C) 1996 E lsevier Science Inc.