Location: Cool and Cold Water Aquaculture Research2013 Annual Report
1. Genetic improvement for bacterial cold water disease (BCWD) resistance in diploid fish also benefits triploid fish production. Fish can be susceptible to many diseases such as BCWD. Fish with 3 sets of chromosomes or triploid fish are often grown because they are sterile and therefore grow to a larger size more efficiently, have better fillet quality, and can’t reproduce in the wild, however, they can be more susceptible to the BCWD disease. ARS researchers at Leetown, West Virginia have previously shown family-based genetic selection can be used to rapidly improve resistance of diploid trout (with 2 sets of chromosomes) to BCWD, increasing survival rate in laboratory challenges from 30% initially, up to 80% in just two generations. However, this selection was based on normal diploid fish which have 2 sets of chromosomes. Now the researchers have demonstrated that selection for improved disease resistance as a diploid can translate into improved disease resistance when the fish are made into triploids. Therefore, the improved line of BCWD-resistant trout they developed is of value to producers of both diploid and triploid rainbow trout used for both food production and fisheries purposes. Furthermore, demonstrating hatcheries can select based on the fertile phenotype (diploid) provides hatcheries the advantage of housing half as many fish as they would otherwise maintain if selection for breeding were based on a trait distinctive to triploids.
Weber, G.M., Wiens, G.D., Welch, T.J., Hostuttler, M.A., Leeds, T.D. 2013. Comparison of disease resistance between diploid, induced-triploid, and intercross-triploid rainbow trout including trout selected for resistance to Flavobacterium psychrophilum. Aquaculture. 410-411, 66-71.
Cleveland, B.M., Weber, G.M. 2013. Effects of triploidy on growth and protein degradation during the recovery from feed deprivation in rainbow trout (Oncorhynchus mykiss). Comparative Biochemistry and Physiology. 166:128-137:dx.doi.org/10.1016/j.cbpa.2013.05.017.
Kiess, A.S., Manangi, M.K., Cleveland, B.M., Wilson, M.E., Blemings, K.P. 2013. Effect of dietary lysine on hepatic lysine catabolism in broilers. Poultry Science. 92: 2705-2712. dx.doi.org/ 10.3382/ps.2012-02805.