Genetic parameters of production traits in Atlantic salmon (Salmo salar)

Phenotypic and genetic parameters of biometrical and carcass traits from two pedigreed populations of an Atlantic salmon breeding program were estimated using restricted maximum likelihood. Each of the populations (broodstock and commercial sib test) comprised of the same 200 full-sib families.Heritability estimates for biometrical traits (sw1wt, sw2wt, harvwt, filletwt, harvlen, guttedwt, deheadwt, guts, head, and carcass) were low to high (0.12–0.53); estimates for fillet fat % and colour traits (hue, saturation, and intensity) were low to moderate (0.16–0.33). The heritabilities for yield traits (guttedwt%, deheadwt%, filletdeheadwt%, and fillet%) measured as a ratio of weights, were low (0.009–0.037), due to the two traits being a fixed proportion of each other. In the broodstock population significant sex (P < 0.001) and tank (P < 0.01) effects were found for first and second sea winter weights (sw1wt and sw2wt) with male fish on average 0.14 kg heavier at sw1wt and 2.34 kg heavier at sw2wt.Estimated genetic correlations (rG) between biometrical traits and fillet fat percentage were all positive and ranged from 0.34 to 0.82. Selection for increased harvest weight is expected to produce favourable changes in fillet weight (rG = 0.99) but unfavourable changes in fillet fat percentage (rG = 0.80). Favourable estimates of the genetic correlation between saturation (colour score) and biometrical traits were all positive (rG = 0.23–0.61).