USDA - ARS

Trout-Grains Project

ARS Plant-based Trout Diets

It has long been hypothesized by some people that trout and other farmed fish require fish meal or animal products in their feed. Studies conducted in this Project and in others around the world have shown that fish require specific nutrients, not ingredients. Many of the nutrients found in fish meal that are not present in plant proteins have been identified allowing for the production of farmed fish without fish meal. The exact formulation of the fish meal free diet will determine which nutrients and the amount of that nutrient, which needs to be supplemented.

In general when only plant sources of protein are used in a fish feed, lysine, methionine, threonine, and taurine may need to be supplemented. The minerals potassium and magnesium have also been shown to be beneficial. The vitamin inositol is found in fish meal and trout benefited from supplementation when added to a plant based feed. Listed below is a the ARS plant-based trout feed formula that supports growth equal to standard fish meal based diets in production trials.

Concept4 Formula Report

Product Code: 1 ARS plant-based trout

TRIAL FORMULA (Rounded):

Formula Totals: 100.00

NUTRIENT COMPOSITION: (class 1)

Elimination of Fish Oil from the Feed

In addition to feeding fish meal free diets, there is a lot of interest in removal of fish oil from the feed. A trout feed formula is shown below that shows promise in meeting this need. This diet is currently being fed on an experimental basis at a production farm. In addition, laboratory trials are underway to further refine the levels of omega-3 fatty acid supplements needed to provide a healthful product for the consumer.

CFC4S Formula Report

Product Code: 100 ARS plant-based trout, no marine

TRIAL FORMULA (Rounded):

Formula Totals: 100.00

NUTRIENT COMPOSITION: (Class 1)