Document Type : Review Article


Young Researchers and Elites Club, Sirjan Branch, Islamic Azad University, Sirjan, Iran


Animal agricultural production systems are major sources of nonpoint pollution affecting quality of water sources. Nitrogen has been identified as the foremost source of nonpoint water pollution  and the potential negative impacts of N have become an area of public concern. protein degradation from feed ingredients is an important factorinfluencing AA supply to the duodenum. Ruminal proteolysis determines the amount ofammonia, AA, peptides, and branched-chain VFA available for microbial growth andproliferation. Carbohydrates are the main components in the dairy ration, comprising roughly 60 – 80% of total dry matter (DM) and could supply to 70% net energy lactation (NEL) for high yielding dairy cows. External markers such as 15N or 35S as well as internal markers such as nucleic acids have been used to determine ruminal microbial protein production


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