Microalgal diversity, nutritional profiles, and applications in poultry nutrition: A comprehensive review

Microalgae have attracted significant interest as a new and sustainable option for poultry feed because of their excellent nutritional value and environmental advantages. They are rich in carbohydrates (10% to 50% of dry weight [DW]), proteins (40% to 65% of DW), lipids (approximately 50% of DW), vitamins and minerals (2.2% to 4.8% of DW), making them excellent additives to conventional poultry diets. In addition to their nutritional value, they also possess antioxidant, antimicrobial, and anti-inflammatory properties. They have the potential to enhance growth performance (approximately 22%), decrease feed conversion ratio (approximately 10%), increase meat and egg production, and boost immune function in poultry. Moreover, adding microalgae to poultry diets has been associated with a reduction in pathogenic microorganisms and an augmentation of the nutritional quality of poultry products such as eggs and meat that are enriched in fatty acids and carotenoids. However, challenges such as the high initial cost of production, scalability of algae farming, regulatory drawbacks, must be addressed to utilize their full potential. Therefore, this review focuses on the nutritional properties of various microalgal species used in poultry feed and their role in poultry health and production. It also explores microalgae industry's present state, challenges, and prospects.