Estimates of phenotypic and genetic parameters for carcass traits in Atlantic salmon and rainbow trout

Abstract

Eight carcass traits were recorded at slaughter for three year-classes of Atlantic salmon and rainbow trout. In both species ungutted and gutted body weight and body length were significantly influenced by sex. In rainbow trout sex also had a significant effect on dressing percentage and score for meatiness. It was concluded that, when ranking families, correcting for sex might be important. In both species the coefficient of variation for body weight was about 30%, and about three times as high as for body length. In Atlantic salmon the dressing percentage was about 89% (S.D. ± 3.3%) and in rainbow trout about 82% (S.D. ± 4.7%). The heritabilities for body weight varied between 0.38–0.44 and 0.19–0.32, and for body length between 0.33–0.35 and 0.16–0.26 in Atlantic salmon and rainbow trout, respectively. The heritability of the score for meatiness was estimated at 0.16 in Atlantic salmon and at 0.14 in rainbow trout. When transformed to an incidence level of 50% mature, the heritability for maturity was estimated at 0.39 in Atlantic salmon and at 0.21 in rainbow trout. The heritabilities for dressing percentage, score for meat colour and liver colour were all very low and not significantly different from zero. In both species the genetic correlations between ungutted and gutted body weight were estimated at 1.00. The genetic correlations between ungutted weight and length were 0.99 and 0.96; between gutted weight and length 0.92 and 0.84; between ungutted weight and meatiness 0.88 and 0.75; between gutted weight and meatiness 0.98 and 0.77; between length and meatiness 0.89 and 0.75; between ungutted weight and maturity 0.52 and 0.11; between gutted weight and maturity 0.49 and 0.11; between length and maturity 0.28 and 0.16, and between meatiness and maturity 0.22 and −0.15 in Atlantic salmon and rainbow trout, respectively.