Effects of Azomite‐ and Sea Salt‐Supplemented Diets on Growth, Feed Conversion Efficiency, Survival, and Resistance against Edwardsiella ictaluri in Channel Catfish Fingerlings

Abstract

AbstractA study was conducted to investigate the effects of dietary azomite (0.25% or 0.50%) or sea salt (0.5% or 1.0%) on the growth performance and disease resistance of Channel Catfish Ictalurus punctatus. Channel Catfish fingerlings were fed diets that were supplemented with graded levels of azomite or sea salt for 9 weeks in trial 1 and for 5 weeks in trial 2. The growth parameters (weight gain and feed conversion ratio) and survival rate were determined at the end of the feeding trials. The resistance of the fish against Edwardsiella ictaluri infection was also evaluated in those that were fed diets containing 0.5% azomite or 1.0% sea salt in trial 2. The results showed that there was no significant difference in the growth performance of the fish that were fed azomite‐ or sea salt‐supplemented diets compared with control animals (P > 0.05). The mortality rate of Channel Catfish 28 d after the E. ictaluri challenge did not differ significantly between groups receiving different dietary treatments. The results indicate that dietary supplementation with azomite or sea salt at the tested levels had no significant effect on either growth performance or disease resistance against E. ictaluri in Channel Catfish fingerlings.