Algae (Spirulina platensis) and duckweed (Lemna gibba sp) Proteinaceous aquatic bio-mass as feed supplements in livestock and poultry rations-a review

With the high costs of the conventional protein supplements required in producing more quantities meat and its products to meet the escalating demand by the ever increasing human population, it is imperative that other cheaper affordable protein sources should be explored. Such protein rich bio-mass are aquatic plants such as algae (Spirulina platensis) and duckweed (Lemna gibba sp). This paper focuses on attributes and challenges in researches associated with the use of these plants which make it a special contender as protein source in livestock and poultry rations. Algae and duckweed are excellent sources of quality proteins, carbohydrates, essential fatty acids, pigments and vitamins and can form food source for human and animals. At present they are being used as food-web to marine species. They are grown to reduce chemical load and to absorb heavy metals in sewage ponds and are used as raw materials for pharmacy, cosmetic, food and feed industry and also to produce bio-diesel on small scale. Even though, there are some challenges and impediments in utilising these marine sources, they have great potential as feed supplements and can solve scarcity and affordability of protein sources in livestock and poultry rations, when they are produced at affordable costs on large scale. Algae have been used as food source to human and animals due to its excellent nutritional profile. There are very few investigations to utilise algae in ruminant rations due to its large requirements to conduct animal trials. Several research works has been conducted to utilise algae in layer and poultry rations which imparts intense orange yellow colour to egg yolk and meat. There are few investigations on duckweed inclusion as partial/full substitution either wet/dry form in cattle, sheep and goats. Duckweed has been extensively tested in layer and broiler birds and also in other poultry including ducks and quails. Results indicated that, it should be fed in relatively small amounts either fresh or dried form. It is of paramount important that the optimum level of inclusion of duckweed as protein sources should be tested widely to obtain their economic benefits. It is imperative to conduct more research on the development of high productive strains, their growth requirements, their production on large scale, processing techniques employed to reduce moisture content and to eliminate antinutritional factors inherently present in them, before advocating them as protein replacement feed resources in the rations of livestock and poultry.