In order to find out how much fish oil and fishmeal are used in the production of farmed fish, the ratio between the amount of wild fish in the feed and the amount of farmed fish produced is calculated.

This calculation is called Fish In Fish Out (FIFO). By reducing the proportion of fishmeal and fish oil in fish feed, the amount of wild fish that are needed to produce one kilo of farmed fish can be reduced. Three factors are important in the calculation of FIFO. These factors are the number of kilos of fishmeal and fish oil extracted from the wild fish scpecies, the number of kilos of feed farmed salmon eat to increase their weight by one kilo and the amounts of fishmeal and fish oil that are used to in the formulation of the fish feed.
Fishmeal and fish oil have traditionally been used as the main ingredients in feed for farmed salmon. Less of these ingredients are now used, and studies carried out by NIFES show that it is possible to produce one kilo of salmon with less than one kilo of wild fish.

How much wild fish is used?

In order to illustrate how much wild fish is used to produce salmon when the feed ingredients vary, the table below shows the FIFO calculations from three different feed trials carried out by NIFES on large salmon. The figures that the FIFO calculations in the table are based on are from three research projects, and include fishmeal and fish oil-based feed, and feed where fishmeal and/or fish oil has been replaced in part by plant ingredients. In commercial farmed salmon feed, fishmeal and fish oil are replaced by a proportion of other feed ingredients such as plant proteins and vegetable oils.

Table: Kilos of raw materials from wild salmon per kilo of produced farmed fish (FIFO)

The table shows kilos of raw materials from wild salmon per kilo of produced farmed fish which is called FIFO.
Fishmeal (kg/kg feed)Fish oil (kg/kg feed)Plant meal (kg/kg feed)Vegetable oil (kg/kg feed)


Fish oil from wild fish with 12% fat contentFish oil from wild fish with 8% fat contentFish oil from wild fish with 5% fat content

Examples of FIFO calculated from five fish feeds used in various research projects* with three levels of fish oil yield from wild fish (5%, 8% and 12%). The actual feed factors from the trials are used in the calculations of FIFO. In feeds 1, 3, 4 and 5, the raw materials from wild fish have been replaced with vegetable oils and/or plant meal*1: RAFOA, feed conversion factor (FCR) = 1.3. 2A and 3 : AquaMAX, FCR = 0.9. 4 and 5 : Whole chain, estimated FCR = 1.2.

The calculations made for feed 2, which only contains fishmeal and fish oil, show that FIFO will vary from 2.1 to 5 depending on the fat content percentage of the fish species the oil is produced from. In the four other feeds, fish oil and/or fishmeal have been replaced by plant ingredients, and FIFO also varies here. Both the fish species the fish oil has been produced from, and the amounts of fishmeal and oil that are used in the production of feed will affect FIFO.

What does FIFO mean for salmon as an EPA and DHA source?

The European Food Safety Authority (EFSA) recommends that a healthy person’s daily dose of the marine omega-3 fatty acids EPA and DHA should be 250 milligrams in order to prevent the development of cardiovascular disease. To cover this reccommendation, one must eat 28 grams per day of salmon produced with a low FIFO (0.5-1.3), or one meal per week (200g). Farmed salmon is then a very good source of EPA and DHA, also when a lot of the fish oil is replaced with vegetable oils and the dependence on wild fish as an ingredient in the feed has been sharply reduced.

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