Genetic variation in mineral absorption of large Atlantic salmon (Salmo salar) reared in seawater

Apparent absorption coefficients (AACs) of mineral elements (K, Na, Cu, Ca, Mg, Zn, Fe, Mn, P) were studied in 82 full-sib family groups of individually tagged Atlantic salmon (41 sires, 2 dams per sire, 7-27 fish per family), with an average weight of 4.6 kg. The fish were kept in one net-pen in seawater and fed a diet with Y2O3 as the inert marker. Faeces were obtained by stripping and pooled for each family. The mean AACs (%) of elements and ash were: K, 97.5; Na, 23.8; Cu, 55.9; Ca, - 11.7; Mg, -260; Zn, 37.9; Fe, 23.8; Mn, 7.6; P, 40.4 and ash, 16.6. Differences between paternal half-sib families were significant (P < 0.05) for the AACs of K, Ca, Mg, Zn and Fe. The sire component explained 54-81% of the variation in the AACs of the elements and 60% of the variation in the AAC of ash. The AACs of all elements, except K, were significantly correlated with AAC of ash. The AACs of Cu and Mg were positively correlated to the mean weight of each family. The AAC of Mg was positively correlated while those of K and Zn were negatively correlated to specific growth rate. The results indicate genetic variation in AACs of elements in Atlantic salmon. (C) 2001 Elsevier Science B.V. All rights reserved.