The use of HUFA-rich algal meals in diets for Litopenaeus vannamei

A 15-week growth trial was conducted with juvenile, Pacific white shrimp Litopenaeus vannamei to study the efficacy of using algal meals as a source of highly unsaturated fatty acids in practical diets that are designed to contain no marine protein or oil sources. Based on previous study, a practical diet was designed containing co-extruded soybean poultry by-product meal with egg supplement and soybean meal as the primary protein sources for formulations containing 350 g kg(-1) crude protein and 100 g kg(-1) lipid. To further refine the diets, the fish oil in two of the diets was completely substituted with plant oils and oil originating from microbial fermentation products rich in docosahexanoic acid (DHA) and arachidonic acid (ArA). A commercial shrimp feed was also included in the trial for comparison. The mean values for shrimp final weight (17.8 g), yield (537.7 g m(-2) or 703.2 g m(-3)), survival (98.5%) and feed conversion ratio (1.4 : 1) showed no statistically significant differences between diets. The results suggest that co-extruded soybean poultry by-product meal and oil from heterotrophic microalgal fermentation sources can be potential candidates for fish meal and marine oil replacement in shrimp diets.