The influence of dietary lipid inclusion and daily ration on growth and smoltification in 1+ Atlantic salmon (Salmo salar) parr

• Published in: Aquaculture
• Main Authors: Berrill, Iain, Porter, Mark J R, Bromage, Niall R
• Other Authors: Institute of Aquaculture, University of Tasmania, University of Stirling
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2004
• Subjects: Atlantic salmon; parr; growth; smoltification; Nutrition; Fishes Growth; Fishes Nutrition; Fishes Feeding and feeds; Salmo salar
• Online Access: http://hdl.handle.net/1893/416; https://doi.org/10.1016/j.aquaculture.2004.08.029; http://www.sciencedirect.com/science/journal/00448486; http://dspace.stir.ac.uk/bitstream/1893/416/2/PAPER%20FINAL.pdf; http://dspace.stir.ac.uk/bitstream/1893/416/1/PAPER%20FINAL.doc

The effects of diet regime on growth and smoltification in 1+ Atlantic salmon parr were studied. Two groups of approximately 400 salmon parr, in triplicate, were fed diets containing either 25% or 12.5% lipid from first-feeding. Two further treatments were fed either the 25% or 12.5% lipid diet for 98 days, after which they were fed the alternate diet. In a second experiment three groups of 550 parr, in duplicate, were fed at full, two-thirds or one-third of the manufacturers’ recommended ration, from first-feeding. All groups were maintained on their respective diet regimes until smoltification approximately one year after first-feeding. In experiment 1, lipid level had a significant effect on whole body lipid content. However growth and the incidence of smoltification was not affected by dietary lipid inclusion, with upper modal group fish from each treatment achieving a similar smolt status (in terms of condition factor and Na+, K+-ATPase) at seawater transfer. In experiment 2, growth and the incidence of smolt transformation increased with ration. Full and two-thirds ration fish maintained similar body lipid contents throughout the experiment, with that of the one-third ration fish lower only during early development, indicating that growth was controlled by the maintenance of a distinct lipid level. It is concluded that ration, and not dietary lipid inclusion, has a significant effect on growth and the decision to undergo smoltification in salmon parr.