Replacement of fish meal in juvenile channel catfish, Ictalurus punctatus, diets using a yeast-derived protein source: the effects on weight gain, food conversion ratio, body composition and survival of catfish challenged with Edwardsiella ictaluri

Abstract

We examined the effects of a yeast-derived protein source (NuPro®) as a replacement for menhaden fish meal on weight gain, specific growth rate (SGR), food conversion ratio (FCR), whole-body composition and disease resistance in juvenile channel catfish (9.9 ± 0.2 g fish−1). NuPro® replaced fish meal at six levels (0, 25, 50, 75, 100 and 125 g kg−1 diet). Catfish were sampled for whole-body composition and then challenged with the bacterium Edwardsiella ictaluri. Growth performance was negatively affected (P < 0.01) when NuPro® was added at 125 g kg−1 diet. The amount of whole-body fat decreased (P < 0.05) when NuPro® was added at 75 g kg−1 or more of the diet. Regardless of the amount of NuPro® added, survival after challenge with E. ictaluri was similar among treatments. Results indicate that up to 100 g kg−1 of NuPro® can be added without negatively affecting growth performance. The yeast-derived protein source used in this study is a sustainable protein alternative that could be used as a partial replacement for fish meal in juvenile channel catfish diets.