Initial Observations on the Inclusion of High Protein Distillers DriedGrain into Rainbow Trout Diets

摘要

An initial investigation into the inclusion of high protein distillers dried grain with solubles (HPDDG) injuvenile rainbow trout Oncorhynchus mykiss diets was conducted during a 36-day feeding trial. Four experimental dietscontaining either 10% or 20% HPDDG with supplemental amino acids, and either with or without phytase, werecompared to a fish-meal-based, non-HPDDG, diet. There was no significant difference among any of the diets in totalweight gain, percent weight gain, feed conversion ratio, or percent mortality. There was also no significant difference inlength, weight, condition factor, hepatosomatic index, viscerosomatic index, or any fish health parameter in fishes fed anyof the diets. Fillet composition, as determined by crude protein, crude lipid, water, and ash were also not significantlydifferent from fish reared on any of the diets. Estimated protein digestibility coefficients were significantly less in the fishreceiving the diet void of HPDDG compared to any of the other diets. The addition of phytase had no effect on anyrearing parameters. The results suggest that HPDDG, if supplemented with essential amino acids, may be included atconcentrations of at least 20% (dry weight) in rainbow trout diets and that more detailed investigation into the use ofHPDDG is warranted.