pAs the global demand for meat increases due to population and economic growth, more pressure has been placed on the animal feed sector to support sustainable livestock production, whilst also ensuring the nutritional value and palatability of feed. With traditional sources of protein, including oilseeds and distiller grains, considered as major contributors to climate change, there is growing interest in establishing alternative, more 'climate-smart' sources of protein, such as seaweed and other forms of microalgae that can supplement livestock diets.ppbrppSeaweed and microalgae as alternative sources of proteinem summarises current advances in utilising macroalgae and microalgae as alternative sources of proteins. The collection reviews processes of protein formation in macroalgae and microalgae, macroalgae farming and processing as well as microalgae bioprocessing. Chapters also discuss the practical application of seaweed as an alternative protein source in ruminant, pig, poultry a