Protein sparing effect and nutritive significance of lipid supplementation in carp diets.

Although carp is in a position to utilize carbohydrates efficiently, lipids are an important energy source in carp diets. In general fat-enriched high-energy diets result in rapid growth and favourable feed conversion. Many authors emphasize the protein-sparing effect of lipid supplementation in carp diets. For efficient protein-utilization an optimal protein/energy ratio in feed is necessary. Good results may be obtained with diets containing 30-50% high-quality protein, > 14 MJ digestible energy/kg and a lipid level of at least 15%. Low protein-high energy diets bring about low nitrogen excretion which is important for maintenance water quality. Lipid-supplemented diets lead to increased lipid content in the carp. Fingerling carp with high fat deposits exhibit an improved overwintering ability. By using fish oil as lipid source it is possible to produce carp meat with high concentrations of n-3 polyunsaturated fatty acids which are beneficial for human health.