Seaweed as a functional feed supplement in animal diet-A review

Seaweeds or marine macro-algae are multicellular organisms that grow abundantly along the coastal line. The use of seaweeds as animal feed is a very common practice in coastal areas since ancient times. Generally, seaweeds are categorized into green, brown, and red seaweeds, based on their colouring pigments. Commercially, seaweeds are used as a source of phycocolloids, fertilizer, livestock feed, and for direct human consumption. The use of seaweeds as livestock feed gained much importance in recent years, as they have good nutritive value and also contain a variety of bioactive compounds that are responsible for many health related benefits. The bioactive compounds of seaweeds exhibit prebiotic, antimicrobial, antioxidant, anti-inflammatory, anticancer and immunomodulatory effects. Over the years, the beneficial effects of using seaweed in animal diets have been studied and reported by many researchers to promote the health and productive performance of livestock. In particular, the brown seaweeds were explored extensively as livestock feed because of their large size. The nutrient value and bioactive compounds concentration in seaweed varies with the species, growing conditions, habitat, environmental changes, season, harvesting procedure, and time. While including seaweed in animal diets all these factors should be taken into consideration. In this review, all the studies related to seaweed supplementation in animal diets will be discussed with a special focus on the potential health benefits.