The study builds on an extensive literature review, a survey, and in-depth interviews to investigate the potential of 10 microalgae and macroalgae production systems in contributing to animal feed requirements in the EU. It summarizes the current state of knowledge in terms of biomass, nutritional yields, costs and greenhouse gas (GHG) emissions. The report also compares production systems against land-based crops (e.g. soya) with similar nutritional properties. Finally, it assesses the EU potential for algae production that could be supported by current CO2 point-source emissions and that could contribute to (today and in the future) animal’s feed requirements. Overall, as algae production is an area where production and Research & Development are evolving in parallel, there is significant variability in values estimated for the criteria investigated. Follow-up research is required in particular on: additional macro- and microalgae species, as well as additional land-based production systems; postharvest processing to support upscaling of biomass production in a sustainable manner and to remove unwanted minerals; and improvement of nutritional value (e.g. digestibility and assimilation) of cultivable algae for animals.