Genetic Differences in Resistance of Farmed Channel Catfish (<em>Ictalurus Punctatus</em>) Crossbreeds to Enteric Septicemia and Columnaris Diseases

Abstract

Six different crossbreeds of channel catfish, Ictalurus punctatus derived from the South-east Fish Culture Laboratory (SFCL), Arkansas Foundation (AKFF), Hopper Steven (HS), BlackBelt (BB) and Goldkist Farms (GK1 and GK2), all in the USA, were evaluated at SouthFresh Farms, West Alabama, for resistance to enteric septicemia of catfish (ESC), and columnaris in May and June 2001. Fish were challenged in tanks with laboratory cultured isolates of Edwardsiella ictaluri and Flavobacterium columnare, the causative agents of ESC and columnaris disease, respectively. The AKFF × SFCL (female × male), GK1 × GK2 and BB × HS crossbreeds had higher (P < 0.5) resistance to ESC compared to the remainder of the crosses. Differences were also observed between reciprocal crosses in resistance to ESC. No differences (P > 0.05) were observed in resistance to columnaris among crossbreeds evaluated. Crossbreeding has potential for improving resistance of farmed channel catfish to E. ictaluri epizootics.