Sustainable alternative animal feeds: Recent advances and future perspective of using azolla as animal feed in livestock, poultry and fish nutrition

Azolla is a small, free-floating water fern with a global distribution. Azolla can be used as a feedstock because it is high in proteins, fatty acids, amino acids and vitamins. Low economic productivity in some countries due to increased import costs is still ongoing if the future still depends on the same sources of protein, i.e. soybeans and maize. This paper reviews the studies on the use of azolla in livestock, poultry and fish nutrition as a promising source of a feed ingredient. A systematic literature review according to PRISMA method was performed using Scopus, Science Direct and Pubmed. Only studies conducted using primary data were considered. Protein content in azolla species is in a range of 21–26%, dry matter, while fatty acids ranged from 41% to 66% dry matter. Azolla is rich in various classes of active compounds such as phenolic content, caffeoylquinic acid derivatives, tannins, and carotene. Azolla has been shown to improve the growth rate of animals, depending on the percent of inclusion in animal's diet. The most common species of azolla used as animals' feedstock is Azolla pinnata. The impact of azolla as a feed ingredient in the food production system on the environment has been addressed, including greenhouse gas emissions, carbon footprint, low land requirements, and amino acid-enriched feedstuffs. Future study on labour cost minimization, life cycle analysis, and optimization techniques should be carried out. •In this review, recent advances of Azolla as animal feed in livestock, poultry and fish farming has been discussed.•The nutritional value and phytochemical features of Azolla, as well as the potential effect of each constituent as an animal feed, have been reviewed.•Azolla dietary inclusion levels of less than 15% in poultry, 5% in broiler chicken, and less than 25% in fish nutrition are recommended.•Sustainability status of Azolla as animal feed in terms of environmental effect has been further reviewed.•Future research of Azolla as sustainable animal feed has been discussed.