Oxygen and feed intake

To what extent is oxygen a limiting factor in the feed intake of fish? Researchers are trying to answer this question in the OXYCOFI project.

They hope that this will increase their understanding fish physiology, which in turn may be of benefit to fish farmers.

A fish’s feed intake is related to oxygen availability. Previous research has shown that fish automatically eat less in water with lower concentrations of oxygen. In this study scientists are examining the extent to which the type of feed influences feed intake in tilapia and rainbow trout. The question is whether high-energy carbohydrate-rich feed – which requires high levels of oxygen for its digestion – limits fishes’ feed consumption. And what about high-fat or protein-rich feed? In addition, the researchers want to know whether the acidity or temperature of the water has an effect on feed intake.  

The goal of the research is primarily theoretical: to what extent does oxygen play a regulatory role in feed intake? The results of the research may also have practical applications. If farmed fish have to switch from animal- to plant-based feed – which would help to reduce the global demand for animal proteins – this may well have important consequences for fishes’ feed intake and therefore also their growth.


  • Effect of dietary macronutrient composition on voluntary feed intake and energy metabolism in rainbow trout (to be submitted).
  • Control of voluntary feed intake in fish: a role for dietary oxygen demand in Nile tilapia (Oreochromis niloticus) fed diets with different macronutrient composition (to be submitted).