“…In ruminants, we can use urea with feeds directly 1-2%, or treated roughages to prepare 3.3% nitrogen (13) or treated grains (25). Adding urea directly requires great attention aimed to eliminate its negative aspects by providing 1-2%, gradually feeding, well mixing feed, frequency of feeding, giving compounds such as N-Carbamylglutamate ( NCG) 0.4 -0.6% as additives, providing clean water, avoid hot weather, having cement floors for the barn with good drainage, in the rumen, In ruminants, urea is commonly used in feeds to reduce costs (5), but it may cause problems for the fetus, because of urea hydrolysis rapidly to NH3-N by rumen microorganism's enzymes within 2h (15) and it is widely used as nonprotein nitrogen (NPN) to provide ammonia that required for rumen microbial growth as true protein for the host animal or ruminants (4,13). The high cost of feed ingrediants need to substitute with cheap sources or by-product.…”