Conversations: Ask your nutritionist how amino acid balancing enhances profitability
Nutritionists who stay up on new technology give their producers a competitive advantage. As producers and their advisors meet in the conference room (or kitchen), a conversation should turn to how amino acid balancing may reduce ration costs, raise the efficiency of milk production, aid in the overall herd health, and be streamlined by today’s software.
By Dan Luchini, Ph.D.
Nutritionists know amino acids (AA) are essential nutrients, not optional dairy feed additives. When rations are balanced with the proper levels of essential AAs, dairy herds can produce more milk, typically with higher components, and have better reproduction and health. At the same time, when done right, ration costs may decrease.
On the other hand, when essential AA levels are not where they need to be, the efficiency of milk production suffers along with reproduction and health. Ration costs are higher than they need to be, as the diet’s protein probably is being overfed.
Using today’s software, nutritionists can readily handle the complex interactions of ruminant protein metabolism. Commercial software programs are designed to do the math involved in formulating rations for maximum nitrogen utilization.
1) Why be concerned with AA balancing?
Historically diets have been defined by their crude protein (CP) content, actually a reflection of the diet’s nitrogen content. Top nutritionists today, however, think in terms of AA levels, the building blocks of protein. AA levels and CP levels are similar but different. AAs and proteins both contain nitrogen. So do other feed components, such as urea and ammonia, but they are not true proteins. Their nitrogen, though, contributes to the diet’s CP content. Therefore, judging a diet’s quality by its CP can be misleading. Judging a diet by its AA composition is better: more accurate, more precise.
Of the 20 AAs in feedstuffs, 10 are essential AAs. Each of these must be supplied to the cow since it cannot synthesize them. Without the proper level of these 10 essential AAs, the cow experiences deficiencies which negatively affect her production, performance and health.
Not balancing AAs, virtually by definition, means you are wasting AAs. This is expensive. The ration costs more because a higher CP level typically will be fed. In addition, the cows are spending energy disposing of unused AAs and unused nitrogen is being excreted.
Ask your nutritionist if your rations are being balanced for amino acids. How long have your rations been balanced for AA?
2) How are MP, RDP, RUP and rumen microbial protein related?
Metabolizable protein (MP) includes all the proteins available to the cow for her use. This includes rumen degradable protein (RDP), rumen undegradable protein (RUP), and microbial protein.
When feedstuffs arrive in the rumen, a large fermentation chamber, a massive microbial population breaks down part of the feedstuffs’ protein into peptides, AA and ammonia. The feed protein broken down in the rumen is called RDP. The microbes use the diet’s AA and non-protein nitrogen to feed themselves, thrive and reproduce. Many of the microbes will move with other rumen contents into the small intestine.
In the small intestine, a part of the lower digestive tract, the microbes (rumen microbial proteins) are broken down into individual AAs. The AA profile of rumen microbial protein far better matches the AA profile of milk protein than the AA profiles of any protein in feedstuffs. The AAs are absorbed and used by the cow to produce the protein in milk, meat and to replenish basic metabolic needs. You see, we feed the rumen; the rumen feeds the cow.
Back at the rumen, some feed protein remains intact, not broken down. This protein is known as rumen undegradable protein (RUP). It, however, is broken down in the small intestine. Because the flow of rumen microbial population cannot fully meet the cow’s protein needs, nutritionists include RUP to assure that cows are properly fed.
The AA profile of the RUP must compliment the AA profile of the microbial protein to avoid an AA deficiency. To do this, nutritionists carefully select feeds with the right RUP and/or supplement the diet with specific rumen-protected AAs.
Ask your nutritionist about the MP, RDP & RUP levels of your rations.
3) What are the key essential AAs to worry about?
The two first-limiting essential AAs in North America are methionine and lysine. Fortunately commercial methionine and lysine products are available and have been proven to be effective.
Ask your nutritionist to identify the available sources of supplemental methionine and lysine. Which does your nutritionist use and why?
4) What are the benefits?
Balancing the ration’s AA levels to meet the cow’s needs allows the cow to utilize protein at maximum efficiency. This contributes to higher milk production, higher milk protein, healthy cows, and more cost-efficient rations.
Discuss AA balancing considerations with your nutritionist. What are the next steps to better herd production.