Submitted to: American Fisheries Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/7/2004
Publication Date: 8/20/2004
Citation: Weber, G.M., Silverstein, J. 2004. Evaluating a stress response for use in a selective breeding program for rainbow trout. American Fisheries Society Annual Meeting 2004, Book of Abstracts, abs: SO-24-17.
Technical Abstract: A breeding program to develop improved germplasm for the US rainbow trout aquaculture industry is being conducted at the USDA ARS National Center for Cool and Coldwater Aquaculture. Although current selection efforts are based on growth and disease resistance, stress response is also a concern. Previous work has shown that heritable differences in stress response can be identified by measuring blood levels of cortisol following exposure to a three hour crowding stress. We characterized some of our broodstock families for this stress response. We found the method to be reliable, and we found the mean cortisol level in response to this stressor was significantly greater for families selected for breeding based on growth rate, than for those not selected. Surprisingly, studies of lines of rainbow trout with disparate stress responses have failed to identify substantial benefits of altering stress response through breeding. Our approach is to characterize the stress response of our broodstock families, generate a limited number of low and high cortisol responding lines, and determine the correlation with various performance traits as we characterize them for our broodstock. If a correlation between a stress response and a performance trait is identified, this connection will be investigated further.