The impact of ingredient particle size on shrimp feed

摘要

Diet ingredients consisting of a mixture of fish meal, hard red winter wheat, shrimp meal and soyabean meal were ground from an initial particle size of 603μ to 586, 521, 408, 272, 124, and 69μ geometric mean particle diameter to evaluate their effects on pellet properties, shrimp growth and survival, and cost of grinding. Test organisms in an 8-week growth study were juvenile Pacific white shrimp, Penaeus vannamei, 1.71 g mean weight, stocked into 52-litre glass aquaria at 12/tank (50 shrimp/m2). Pellet water stability, pellet durability, starch gelatinization, shrimp live weight, and weekly weight gain were enhanced (P<0.05) by reduction of ingredient particle size to 124μ. Particle size reduction did not have any apparent effect on feed conversion efficiency and survival among shrimp stocked at 1.7 g. The energy required to grind was lowest at 586μ or coarser particle size and increased exponentially (r2 = 0.91) as the ingredient particle size became smaller.