Amino acids, which are organic compounds containing basic amino groups and acidic carboxyl groups, are the basic units that make up proteins.
As an important part of the body's tissues, the core of protein nutrition is amino acid balance, especially restriction amino acids. Methionine and lysine are the most important limiting amino acids for growth, hair production, milk production, or milk protein synthesis.
Ruminants grow fast and have a high demand for amino acids, but animals themselves cannot synthesize all the essential amino acids they need, so they can adjust the amino acid balance by supplementing important limiting amino acids such as methionine and lysine in the diet, thereby improving protein utilization efficiency and reducing nitrogen emissions. However, due to the particularity of the rumen in its digestive system, the direct addition of protein or amino acids to the diet will be degraded in the rumen, and only through the amino acids and microbial proteins of the rumen are absorbed and transformed in the small intestine to maintain life activities such as growth, reproduction and lactation.
With the shortage of protein feed resources and the improvement of nitrogen emission control requirements in recent years, when reducing the proportion of crude protein in the diet, additional rumen methionine and rumen lysine to the diet to meet the nutritional needs of ruminants have become a hot spot in industrial research and application.
