New Tractable Selection Criteria for Disease Resistance and Animal Welfare in Fish

Summary

Early variation in metabolic rate may predict other trait characteristics, such as social dominance, growth and timing of sexual maturation and stress responsiveness. This information could be used to optimize rearing regimes, before newly hatched fish enter more cost intensive parts of the production cycle, and also to increase the effectiveness selecting for these traits in a breeding program. Genetic parameters for four traits were investigated. The two new predicative traits, i.e. day-degrees and Swim- up time, showed high heritabilities of 0.41 and 0.38, respectively, but with large standard errors. The genetic correlation between the two new indicative traits and resistance against IPN was 0.41 and 0.60, respectively. Since the present method is much less laborious and cost-efficient than other methods for measuring stress response, it should be an attractable alternative selection criterion for disease resistance in many breeding programs. The present study has thus demonstrated the use of non-invasive and cost efficient new selection criteria for disease resistance and animal welfare. Further studies to establish more conclusive estimates of the genetic parameters are needed.