Amino acids are the building blocks for protein, one of the most critical nutrients in the dairy cow ration. While the benefits of amino acid balancing can be great— increased milk and components, reduced ration costs and improved feed efficiency—the practice of balancing for these protein building blocks is often overlooked. Understanding the role amino acids play and why they are critical to the diet can help deliver a more precise ration for boosting performance and maintaining a healthy herd.
The science behind protein
The sequence in which amino acids are combined determines which protein is created. The amino acid that limits protein synthesis is called the first limiting amino acid, explains Dr. Essi Evans, CEO of Essi Evans Technical Advisory Services Inc. in Ontario, Canada. While any amino acid can be limiting, those termed essential— meaning the cow cannot readily synthesize them—are usually most limiting. Frequently, the first limiting amino acids are lysine and methionine, and these essential amino acids can only be supplied through the diet.
“Amino acid requirements are uniquely different than any other component of the ration,” says Dr. Evans. “The amino acid composition of each protein will always be the same; if a particular amino acid is not available, the entire protein cannot be synthesized. There is no way to substitute alternative amino acids for the missing one.”
A balancing act
Balancing rations for amino acids isn’t as simple as feeding specific amino acids, says Dr. Evans. Along with accounting for feed breakdown in the rumen, finding a cost-effective, consistent source of limiting amino acids can be difficult.
“In ruminant animals, the effects of the rumen microbes must be taken into account,” explains Dr. Evans. “We need to estimate the extent to which the protein in feeds is degraded in the rumen as well as the amount of microbial protein that will be produced. This adds a level of difficulty to solving the amino acid needs of the dairy cow.”
Because of this difficulty, rations are often created that are not balanced for amino acids, which can be detrimental to performance and eliminate the ration consistency cows crave.
“If diets are simply balanced for protein levels or protein solubility, performance can change each time a ration is reformulated. Nutritionists will not be able to determine if amino acid requirements are being met by balancing for protein alone,” shares Dr. Evans.
Amino acid balancing today, in the future
Several programs are available to help nutritionists balance rations for amino acids. A number of protein products, such as soybean meal and animal byproduct blends, are made with strict standards to ensure amino acid levels remain constant for ration formulation.
“As amino acid technology is accepted by more and more nutritional advisors, a great number of products targeting specific problems can be expected to appear on the market,” says Dr. Evans. “As well, programs will continue to evolve, allowing for tighter, more precise ration formulations.”
By reaping incremental benefits from amino acid balancing, increased ration costs can quickly be offset by improved milk and component production, lower ration protein costs and improved efficiencies. Talk to your nutritionist to learn more about the benefits of amino acid balancing.
Source: Arm & Hammer Animal Nutrition