Alpharetta, GA (April 30, 2019)
Knowledge of dairy nutrition and methionine continues to evolve. Over time, the amino acid methionine has come to be recognized as an essential nutrient. Methionine cannot be synthesized in the quantity required for normal health, and feedstuffs cannot fill the nutritional requirement without overfeeding protein.
The research, which stretches back to the 1970s, shows that regularly meeting the methionine needs of dairy cows supports not only production – milk, milk protein, and milkfat – but also animal health and reproduction. This includes metabolic diseases, timely breed backs, and full-term pregnancies.
Methionine is heavily involved in the metabolic pathways of dairy cows. It is considered the enabler of all protein synthesis and, thus, the origin of life. After the role of methionine was well established for optimizing production responses, research focused on the additional impacts of methionine on herd health and performance, according to Dr. Daniel Luchini, Global Ruminant Product and Technical Services Manager, Adisseo.
“With the realization that methionine is more than milk — more than milk and milk components, we began applying these insights. We began optimizing the efficiency of nitrogen utilization not only for milk production, but also for health and reproduction. In essence, we took a step forward in realizing the genetic potential of dairy cows,” says Charles Schwab, Professor Emeritus, Animal Science, University of New Hampshire; Principal, Schwab Consulting. “Now we’re seeing daily supplementation with limiting amino acids becoming as common as daily supplementation with vitamins and minerals.”
Methionine was first identified as an essential amino acid for dairy cows in the 1970s. Rumen-protected methionine products were introduced during the 1990s to support increases in production levels. In 2001, the National Research Council (NRC) concluded that methionine and lysine were the two most limiting amino acids in dairy diets and speculated that the identification of other limiting amino acids would follow. It recommended a lysine-to-methionine ratio and minimum concentrations of each in metabolizable protein to optimize milk protein output.
In the 2010s, the introduction of rumen-protected lysine products brought the flexibility to formulate rations to even more precisely meet the amino acid requirements of dairy cows. Now the first two limiting amino acids could be supplied more easily in the right ratio and right quantities.
At the same time, the movement away from a focus on ration crude protein to metabolizable protein and then to amino acids accelerated. In fact, it is now recognized that metabolizable protein as a proxy for estimating total amino acid supplies and requirements has its limits. Advancements in the Cornell Net Carbohydrate and Protein System (CNCPS) testify to this, according to Professor Mike Van Amburgh, Department of Animal Science, Cornell University. The industry is now progressing rapidly to formulating diets based on grams of methionine and lysine per MCal of metabolizable energy as the most efficient way to meet both amino acid and energy requirements. Optimized diets deliver balanced nutrition at the least cost.
