The concept of amino acid balancing is nothing new to the dairy industry. The tools needed to effectively balance amino acid dairy rations have been readily available for more than 10 years. The degree of economic return with amino acid balancing fluctuates with the pay price on milk protein and, to a lesser extent, milk fat.
The Federal Milk Marketing Order 30 (FMMO 30) applies to most Dairy Star readers. Pay price within the FMMO 30 on milk fat has been higher than protein since last fall, but the volume contribution of both still comprises the majority of your milk check. There are benefits to maximize both milk fat and protein independent of their current market value. We also need to recognize a seasonal aspect to both milk fat and protein, and we are currently at seasonal lows for both (see chart).
Amino acids are the building blocks of proteins. Conceptually, we continue to place less emphasis on dietary crude protein and more emphasis on the available grams of specific amino acids. Numerous ration modeling programs are capable of predicting both the dietary contribution to these amino acids along with rumen microbial contribution.
It is well documented that lysine and methionine are the two most limiting amino acids in a lactating dairy cow diet. Different feed ingredients contribute a wide range of types and amounts of amino acids. Different feed ingredients, as well as synthetic sources, can contribute to lysine and methionine in the diet. However, keep in mind that not all sources are created equal. The bioavailability of these amino acids - and the decision on which feedstuff provides the most economical return on investment - is a conversation to have with your nutrition advisor.
The primary goal with amino acid balancing is to improve protein efficiency. As a result, amino acid balancing often yields an improvement in milk protein output. Although a majority of these benefits come from intestinal absorption of specific amino acids, research has shown benefits in milk yield and milk fat responses to the rumen available contribution.
The benefits of amino acid balancing go well beyond milk component responses. Improvement in protein efficiency results in less excess nitrogen excretion, which inherently has some environmental benefits. It was quite common 15 years ago to see dietary crude protein levels at 18 to 19 percent. Today, we see dietary crude protein levels on amino acid-balanced herds at 16.5 percent or lower. Milk urea nitrogen (MUN) values on these herds are often between 8 and 12 mg/dl. Lower nitrogen excretion results in additional energy that can be utilized for body reserves, milk production or other requirements of the cow.
Amino acid balancing is gathering attention in dry cows, as well. Research has shown cow health benefits and early lactation energy corrected milk improvements with the inclusion of amino acid balancing through the dry period. Calf and heifer programs are also incorporating specific amino acids and realizing positive responses in daily gains.
Consider amino acid balancing and potential improved protein efficiency on your farm. The net results can be improvement in cow health and performance, and an economic return to your bottom line.