Protein by sources of raw materials can be divided into two major categories of animal protein and vegetable protein, including fish meal, meat and bone meal and blood meal, etc are rich in animal protein, because of these proteins contain amino acids and amino acids required for the fish to grow, so the protein is not simply the absorption rate is high, but also absorb quickly, the low degree of water pollution, Therefore, the protein of high quality aquatic feed should be based on this animal protein. However, cottonseed meal, alfalfa meal and rapeseed meal mainly contain plant protein, which is used as the main raw material to produce aquatic feed fish absorption rate is low, slow absorption, serious pollution to water quality.