A defatted microalgae (Haematococcus pluvialis) meal as a protein ingredient to partially replace fishmeal in diets of Pacific white shrimp (Litopenaeus vannamei, Boone, 1931)

Abstract This trial evaluated the effects of partial replacement of fishmeal protein by a defatted microalgae meal (DMM) in a shrimp diet. The DMM was a by-product of astaxanthin production from Haematococcus pluvialis and contained 40.3% crude protein (CP) and 0.9% crude lipid (CL). Test diets were prepared by using DMM (3, 6, 9 and 12% in a diet) to replace 12.5%, 25%, 37.5% or 50% of a fishmeal protein in a control diet (32.3% CP & 8.9% CL). All test diets had similar protein and lipid levels. Each diet was randomly assigned to four tanks (12 juvenile shrimp per tank) in an indoor flow through seawater laboratory. After an 8-week feeding trial, shrimp fed the diet with 12.5% of the fishmeal protein replaced showed a significantly higher growth rate and lower feed conversion ratio than the shrimp fed the control diet (P   0.05). Shrimp fed the four DMM-added diets appeared redder and contained higher free and esterified astaxanthins than shrimp fed the control diet. The results indicated that DMM could be a valuable alternative protein and pigmentation ingredient in shrimp feed.