Grain sprouts as green feed with hydroponic technique: Review of merits and limitations

Hydroponic is an alternative technology to grow green feed without soil. This technology requires less land, water and is resilient to weather conditions, guaranteeing green feed production round the year. This method of producing green feed has both merits and limitations. Cereal grains and legume seeds can be utilized for sprouting to produce green feed. The most commonly used cereal grains are barley and oat in temperate countries, and maize in India due to easy availability and lower cost. During the sprouting process, beneficial changes occur in grain in terms of increased enzyme activity as well as protein content and more bioavailable amino acids and vitamins. The facility for production of grain sprouts can be modern hi-tech type of climate-controlled chambers or low-cost device as per the financial status of the farmer, availability of building material and local conditions. Hi-tech chambers are fully automatic, maintain optimal conditions and yield more biomass but relatively expensive. In tropical countries, low cost devices are more accepted to grow grain sprouts by small dairy farmers. The merit of hydroponic grain sprouts is ease of producing a green feed with better protein and micronutrient profile in a short period for supplementation along with available crop residues like straw and stover, especially in places where there are constraints of land and water. The limitations of this technique include loss of dry matter, reduction in energy content and chances of fungal contamination. Perusal of published reports suggest that the green biomass produced using hydroponic technique is a new category of feed resource and calling it as green fodder may not be appropriate, as it can't replace the conventional forage. Hence, in view of the nutrient profile, merits and limitations of production, grain sprouts can be termed as green feed for strategic supplementation with more utility during contingency situations. The need to review some of the pertinent work done on this aspect has been realized and an attempt is made to provide holistic view from the perspective of livestock feeding.