Malt root: malt root is the by-product of malt workshop of malt factory or brewery. It is produced after barley is soaked and germinated. Malt root is rich in starch enzyme, maltase, fructase and protein enzyme. The protein content of malt root is 25-30.18%, fat is 1.57% and crude fiber is 11.84%; The total content of amino acids was 8.69%, and the content of vitamin B was relatively high It has strong fragrance and is a good protein feed resource. It is suitable for aquatic products, rabbit feed and all kinds of poultry feed.