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This Article Full Text (PDF) All Versions of this Article: jas.2008-1157v1 87/3/860    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Silverstein, J. T. Articles by Ducrocq, V. Search for Related Content PubMed PubMed Citation Articles by Silverstein, J. T. Articles by Ducrocq, V.

Rainbow trout resistance to bacterial cold-water disease is moderately heritable and is not adversely correlated with growth

J. T. Silverstein^*, R. L. Vallejo^*, Y. Palti^*, T. D. Leeds^*, C. E. Rexroad, III^*, T. J. Welch^*, G. D. Wiens^* and V. Ducrocq

^* US Department of Agriculture, Agricultural Research Service, National Center for Cool and Cold Water Aquaculture, 11861 Leetown Rd., Kearneysville, WV, 25430 USA UR337 Institut National de la Recherche Agronomique, Jouy-en-Josas 78352, France

Yniv.Palti{at}ars.usda.gov

Abstract

The objectives of this study were to estimate the heritabilities for and genetic correlations among resistance to bacterial cold-water disease and growth traits in a population of rainbow trout (Oncorhynchus mykiss). Bacterial cold-water disease, a chronic disease of rainbow trout, is caused by Flavobacterium psychrophilum. This bacterium also causes acute losses in young fish known as rainbow trout fry syndrome. Selective breeding for increased disease resistance is a promising strategy that has not been widely utilized in aquaculture. At the same time, improving growth performance is also critical for efficient production. At the National Center for Cool and Cold Water Aquaculture, reducing the negative impact of diseases on rainbow trout culture and improving growth performance are primary objectives. In 2005, when fish averaged 2.4 g, 71 full-sib families were challenged with Flavobacterium psychrophilum and evaluated for 21 d. Overall survival was 29.3% and family rates of survival varied from 1.5 to 72.5%. Heritability of post-challenge survival, an indicator of disease resistance, was estimated to be 0.35 ± 0.09. Body weights at 9 and 12 mo post hatch and growth rate from 9 to 12 mo were evaluated on siblings of the fish in the disease challenge study. Growth traits were moderately heritable, from 0.32 for growth rate to 0. 61 for 12-mo BW. Genetic and phenotypic correlations between growth traits and resistance to bacterial cold-water disease were not different from zero. These results suggest that genetic improvement can be made simultaneously for growth and bacterial cold-water disease resistance in rainbow trout using selective breeding.

Key Words: challenge test • disease resistance • genetic correlation • growth • heritability • rainbow trout