Heritability of mortality in response to a natural pancreas disease challenge in Atlantic salmon post-smolts on a West of Ireland sea site.
^Three different methods of colour measurement of Atlantic salmon flesh were employed in this study; subjective scoring (SalmoFan(TM)), colorimetric measurement and carotenoid content as measured by NIR analysis. Parentage of fish was assigned using a suite of eight microsatellite markers. Genetic parameters were estimated using a restricted maximum likelihood methodology applied to a multivariate animal model. Heritabilities for all colour traits were low to medium with carotenoid content in the flesh exhibiting the lowest additive genetic variation. Genetic correlations between carotenoid content and perceived and colorimetric traits were also lower than all other genetic correlations suggesting that the retention of pigment is not under the control of the same genes as perceived colour. It may be that fillet colour is influenced by factors other than pigment retained in the flesh. Genetic correlations between subjective visual scores (two scorers) and colorimetric measurements were all high with the a* value of the Minolta camera being the most highly correlated with subjectively assessed colour.