Influence of purified soybean phospholipids on early development of common carp

The influence of dietary phospholipid (PL) composition on early development was tested in a 25 day feeding trial with first-feeding common carp (Cyprinus carpio) larvae. A phosphatidylcholine (PC) fraction (PL: 94%, PC: 83%, PI: 1%) and a phosphatidylinositol (PI) fraction (PL: 100%, PC: 3%, PI: 64%) were prepared from soybean lecithin and added (2% on diet dry weight) to a casein-dextrin basal diet. Another diet was supplemented with 2% hen egg yolk PL (PL: 97%, PC: 68%, PI: 0%). A PL-deficient diet contained only peanut oil as lipid source and another one was supplemented with inositol. Final larval morphology was examined by an automatic image analysis system. The three PL fractions markedly improved growth in comparison with PL-deficient diets. Fish fed the PC-rich diets had the highest initial growth rates. Inositol addition had no beneficial effect. The two PC diets induced various deformities such as lordosis whereas the PI diet resulted in the lowest frequency of deformed fish. At the end of the experiment the fatty acid composition of carp was related to the fish size and to the fatty acid composition of the dietary PL. Results confirm that PL is essential for carp larvae and suggest a beneficial role of PI supply