Submitted to: American Fisheries Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2004
Publication Date: 8/20/2004
Citation: Silverstein, J. 2004. The relationships among feed intake, feed efficiency and growth in rainbow trout. American Fisheries Society Annual Meeting.
Technical Abstract: Weight gain and feed intake are strongly correlated in animals. In fish the correlation coefficient between feed consumed and body weight gain is typically greater than 0.7. Individual differences in the efficiency of converting feed into body weight causes this correlation to be less than 1.0. Improving the efficiency of production is important for both economic and environmental sustainability. The purpose of this work is to define the relationships between feed intake, weight gain and feed efficiency (measured as residual feed intake) in rainbow trout fed either to apparent satiation or a fixed ration. The genetic variation for feed efficiency was also examined to determine whether sufficient genetic variation exists to selectively breed for increased feed efficiency. Preliminary results indicate that under an apparent satiation feeding regime a weak but significant correlation exists between weight gain and improved efficiency (r=0.32, P<0.02). Furthermore, significant genetic variation in residual feed intake was demonstrated. When fed a fixed ration, the correlation between weight gain and feed efficiency was stronger (r=0.48, P<0.001), but the genetic variation was not significant. These results suggest that selective breeding for improved efficiency is attainable with the correct feeding regime.