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Improving production efficiency of farmed Atlantic salmon ( Salmo salar L.) by isoenergetic diets with increased dietary protein‐to‐lipid ratio
Author(s) -
Weihe Rúni,
Dessen JensErik,
Arge Regin,
Thomassen Magny Sissel,
Hatlen Bjarne,
Rørvik KjellArne
Publication year - 2018
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.13598
Subject(s) - biology , salmo , feed conversion ratio , zoology , nutrient , protein efficiency ratio , body weight , aquaculture , fish <actinopterygii> , fishery , food science , ecology , endocrinology
The effects of isoenergetic diets with high ( HP ) and low ( LP ) protein‐to‐lipid ratios on feeding rate ( SFR ), feed conversion ( FCR ), growth ( TGC ) and relative‐ and absolute nutrient retention were investigated using both whole‐body weight ( BW ) and carcass weight ( CW ) to assess the production efficiency. Three different feeding trials in seawater were conducted: two large‐scale trials with yearling smolt (S1) and under‐yearling smolt (S0) and one small‐scale with S1 smolt. The initial body weights in the trials were 105, 319 and 978 g, respectively, and the fish were fed and monitored until they reached harvest weights. In all three trials, the dietary HP group attained significantly higher ( p < .05) CW at harvest based on fish with equal BW . Also, fish fed the HP diets significantly improved FCR ( p < .05) when based on CW . In the small‐scale trial, fish fed HP diet, especially during late autumn and spring, significantly ( p < .001) improved FCR BW and FCR CW . Improved FCR coincided with significantly higher ( p < .05) relative energy retention in the dietary HP group. In all three trials, the HP groups had significantly higher ( p < .05) TGC with regard to both BW and CW . Taken together, the present studies indicate that growth performance and feed utilization in modern salmon farming has the potential to be further improved by increasing the dietary protein‐to‐lipid ratio. In addition, dietary influence is more precisely assessed when using carcass as the weight denominator when analysing feed utilization and growth performance.