Effect of omega 3 fatty acid on growth in Atlantic salmon (Salmo salar) aquaculture

Abstract

Background: The effect of diet on fatty acids in Atlantic salmon, particularly omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA), has been understudied due to lack of marine raw materials (fish meal and fish oil). A variety of ingredients are used as replacements for fish meal for Atlantic salmon. The aim of this systematic literature review (SLR) is examining the effect of omega 3 fatty acid on growth in Atlantic salmon. Methods: The present study conducted a systematic literature review to provide a summary of currently available information and to identify the most significant effect of omega-3 levels on growth in Atlantic salmon. Main finding: There were not so many studies which met the inclusive criteria, therefore only 21 of 844 papers were selected from which to extract the data. Indicators for the growth such as weight gain, feed conversion ratio (FCR), and specific growth rate (SGR) have been collected from those papers. This study combined multiple studies and analyzed the output data, but it was not exactly a meta-analysis as it did not measure outcome variables in response to a general control and lack of data. 14 of the 21 experiments demonstrated that the reduction of omega 3 fatty acid had no effect on the growth of the fish. Contradictorily, there were two papers that demonstrated that the omega 3 fatty acid directly influences growth in salmon. 5 of the 21 papers found that the growth performance in salmon has been slightly reduced when the fish were fed with less or no omega 3 fatty acid levels. Almost all of the papers concluded that there was no significant difference in the final weight between experiment groups. Conclusion: A potential trend in aquaculture is to include more plant-based ingredients in fish meal to replace the traditional fish meal- and fish oil-based diet. However, digesting plant material may pose a challenge for the fish, influencing the growth performance. Therefore, the minimum requirement for omega 3 fatty acid levels should be upheld during the process of incorporating ingredients into the feed. Further research is required on the ratio of DHA versus EPA to evaluate how each fatty acid affects the growth of Atlantic salmon.

Keywords: Omega 3, fatty acid, growth, health, Atlantic salmon, aquaculture, systematic literature review