Effect of Dietary Protein on the Response of Rainbow Trout ( Salmo gairdneri ) to Aflatoxin B 1 2 3

Abstract

Diets containing either 49.5% or 32% casein or fish protein concentrate (FPC) were fed to young rainbow trout (Salmo gairdneri) for 12 months. Five levels [0, 2, 6, 18, and 54 parts per billion (ppb)) of aflatoxin B₁ (AFB₁) were given in each of four different diets. A 30-fish sample was taken at 6, 9, and 12 months to determine the influence of diet on the carcinogenicity of AFB₁. Both levels of casein produced similar hepatoma incidences at each level of AFB₁, The diet high in FPC produced more tumors than did the casein diets at 2, 6, and 18 ppb AFB₁ whereas fish fed the diet low in FPC had a significantly (P<0.05) lower hepatoma incidence than did the other three groups. The liver size (percent body wt) was smaller at higher toxin levels in all instances. The growth of fish given 32% casein was less than that of the other groups.