New technology and products make more precise rations possible. With these rations come cost savings, more efficient use of feed resources and the same or better herd performance.
Cost savings, high production levels and reduced nitrogen excretion have earned amino acid balancing a place in ration formulation strategies. Even greater opportunity exists for precision and more predictable performance results.
On individual dairies, determination of the return on amino acid balancing depends on two factors, according to Glen Aines, Ph.D., technical support specialist at Balchem Animal Nutrition and Health. “The return on investment (ROI) depends on herd response and ration cost. In seven recent research studies, the average change in milk components was worth 53¢/cow/day, assuming a protein value of $2.20/lb. and a butterfat value of $1.20/lb.
Chuck Schwab, professor emeritus at the University of New Hampshire and dairy consultant, would expect no less. Dr. Schwab has been involved in amino acid research since the 1970s.
“Historically, nutritionists have used a blend of rumen undegradable protein sources in an attempt to match the cow’s needs,” said Aines. “These feedstuffs, however, go through some transformations during rumen digestion that can further alter their amino acid profiles.”
Considerable variation in amino acid levels exists in common feedstuffs. Table 1 provides some typical values for amino acids in common feeds.
The introduction of protected methionine products simplified amino acid balancing. The protected methionine, one of the first two limiting amino acids, survives the harsh rumen environment increasing availability and absorption in the small intestine. “Yet, some differences among these products exists,” noted Schwab.
Developing a protected lysine product proved far more challenging. Lysine is the other first limiting amino acid. The first rumen-protected lysine was introduced in the fall of 2008. Far more cost-effective and more precise rations followed. Nutritionists are confidently bringing crude protein levels down from 18%-19% to 16.5%-17%. The methionine and lysine levels no longer need to be assured by over feeding protein. Reducing the protein level also reduces ration costs.
Research with the new rumen-protected lysine defines its benefits. The research used a control diet deficient in lysine. Cows were fed 0, 30, or 60 grams of the rumen-protected lysine. All diets contained approximately 16.8% protein, the same energy content and sufficient methionine to prevent methionine from limiting performance. Researchers then measured the specific response to increased lysine.
The decrease in percent crude protein makes room for more of other feedstuffs. “When producers save a pound of protein, they can put in a pound of something else. Why not put in a pound of something that rumen bacteria will respond to such as fermentable carbohydrates? We know that a pound of fermentable carbohydrate is probably good for 2 to 4 lbs. of milk,” said Schwab.
Use of amino acid balancing to decrease crude protein while maintaining or increasing performance is also good for the environment. Bringing down ration crude protein levels decreases nitrogen excretions.
Recently, use of distillers grains from ethanol production has received research attention. Both corn and distillers grains are naturally low in lysine.
“In scenarios where we’re seeing a lot of corn-based products and byproducts in the ration, adding a protected lysine product certainly could benefit,” said Ken Kalscheur, Ph.D., associate professor of Dairy at South Dakota State University. “The question is ‘what ingredients are you using and what impact does that have in formulating for specific amino acids?’ ”
He looks forward to using the new rumen-protected lysine product in distiller-grains-based diets and seeing how it does on individual dairies. “I definitely think there are areas where it can be used, but it comes down to cost,” he said. “If it’s cost effective, people will adapt.”
Processing affects lysine
Inconsistency in byproduct feeds poses a potential problem when formulating for amino acids particularly for lysine where bioavailability can be significantly reduced by processing. Lysine levels, ruminal bypass and intestinal absorption vary with the feedstuff and its processing. A good example of this is blood meal (see the Table 3).
Amino acid balancing
The process starts with the software for ration formulation. Many allow for amino acid balancing. Guidelines or assistance with balancing amino acids is available from most suppliers of rumen-protected methionines and lysine. The following steps lay the proper groundwork, according to Schwab.
1) Balance the ration for fermentable carbohydrates, such as high-quality forages and finely ground or steam-flaked cereal grains and adequate effective fiber.
“Fermentable carbohydrates support good rumen health and maximize microbial protein synthesis,” Schwab said. “Because microbial protein has a superior amino acid profile to rumen undegradable protein (RUP), higher microbial protein production allows nutritionists and producers to feed lower levels of more costly RUP.
2) Balance for methionine and lysine, the first two limiting amino acids. Replace low-lysine feeds with high-lysine protein supplements or the new rumen-protected lysine product.
“Many producers and nutritionists are moving from rations with 18%-18.5% crude protein to rations with 16%-16.5% crude protein,” Schwab said.
“The 2% difference in ration can now be filled with fermentable carbohydrates which support milk production,” he said.
Well managed herds can respond quickly. “We find that cows really respond,” said Schwab. “We’ll see the milk protein percent respond in just a few days. The full effects of the milk fat percent take longer, but typically appear within a month. Over time, the change in milk protein percent typically becomes more pronounced.”
Other typical expectations include:
• Increased use of homegrown feedstuffs
• Lower ration crude protein levels
• Feeding of more roughage to fill space created in the ration
• Increases in milk yield and components
• Reduced protein costs for reduced ration costs
• Less excretion of nitrogen into the environment
Facts about amino acids
• Dairy cows have nutritional requirements for specific amino acids; not for proteins.
• Essential amino acids cannot be made by the cow. They must be obtained from feedstuffs
• Non-essential amino acids can be made by the cow.
• Amino acids can be derived from either the microbial protein produced by microbial populations in the rumen (the highest-quality protein available to the cow) or from feedstuffs that are not broken down in the rumen, but are broken down in the intestine and absorbed.
• For efficient amino acid use, maximize microbial protein production and feed rumen undegradable protein (RUP) with an essential amino acid profile that mirrors the cow’s essential amino acid requirements.
• Chuck Schwab is professor emeritus at the University of New Hampshire and dairy consultant. E-mail: Charles.Schwab@unh.edu. Phone: 603-862-1341
• Ken Kalscheur is associate professor of dairy at South Dakota State University. E-mail: email@example.com. Phone: 605-688-5482
• Glen Aines is technical support specialist at Balchem Animal Nutrition and Health. E-mail: firstname.lastname@example.org. Phone: 402-305-3909.