The characteristic of puffed urea (sustained release urea) is that rumen microorganisms can convert non-protein nitrogen into microorganisms, that is, bacterial proteins, and microbial proteins enrich the amino acids absorbed by animals, so that the protein nutrition of animals has been improved. In fact, non-protein nitrogen plays a role in protein nutrition, so the use of puffed urea as a substitute for protein feed for ruminant livestock such as cattle is a solution to the current protein feed shortage. It is also an important raw material for reducing feed costs.