Genetic variation in feed intake, growth and feed utilization in Atlantic salmon (Salmo salar)

Feed intake, growth and feed utilization were studied in 14 full-sib family groups of Atlantic salmon (seven sires, two dams per sire, 30 fish per fam ily), with an average initial body weight of 148 g. Each full-sib family wa s held in replicate tanks with fresh water for two subsequent 5-week period s. Body weight increased by 12-52%, and the average daily feed intake (DFI) , thermal growth coefficient (TGC) and feed efficiency ratio (FER) were 0.3 3% of BW (CV = 21), 1.08 X 10(-3) (CV = 35) and 1.14 g weight gain/g feed i ntake (CV = 16), respectively. The effects of family and growth period on D FI, TGC and FER were significant (P < 0.05), with family explaining 31-32% of the variation. FER was positively correlated with TGC (r = 0.79, P < 0.0 01, n = 28). The salmon consumed an average of 450 g protein (CV = 16) and 22.6 MJ gross energy (CV = 18)/kg gain: 43% of the protein and 31% of the e nergy were deposited. When calculated per kilogram weight gain, the effects of family were significant for feed consumption and visceral deposition of protein and energy. The results indicate a genetic variation for feed inta ke, growth and feed utilization in Atlantic salmon. (C) 2001 Elsevier Scien ce B.V. All rights reserved.