Balancing for optimal amino acid levels can result in the greatest milk and protein production response, while also reducing dietary protein needs. However, delivering limiting amino acids at optimal levels has been a challenge for nutritionists for quite some time.
Delivering optimal levels of lysine and methionine has been particularly challenging because a rumen bypass lysine source has not always been available, says Dr. Charlie Sniffen of Fencrest, LLC, in Holderness, New Hampshire. Without a cost-effective bypass lysine option, it’s especially difficult to measure the amount of lysine reaching the small intestine.
“In the past we over-formulated diets for amino acids to elicit a milk and protein production response. This feeding strategy can be expensive and result in large amounts of nitrogen excretion due to overfeeding protein,” explains Dr. Sniffen. “When nutritionists couldn’t reach optimal levels they aimed for more practical levels. While this strategy provides lysine and methionine in the proper 3:1 ratio, peak performance could not be met because optimal levels were not reached.”
The greatest benefit with optimal supplementation
Research1 confirms production improvements can be realized when optimal levels of lysine and methionine are provided.
Sixty Holstein cows were assigned to one of four dietary treatments:
Group 1: 18.3 percent crude protein (CP), low rumen undegradable protein (RUP)
Group 2: 18.3 percent CP, high RUP
Group 3: 16.9 percent CP, high RUP
Group 4: 17.0 percent CP, high RUP + bypass methionine (optimal lysine and methionine levels)
The results show cows fed reduced crude protein diets balanced for amino acids (Group 4) produced significantly more milk and milk protein, with greater feed efficiency than cows fed higher crude protein with a low amount of bypass protein and amino acids (Group 2).
“By providing the optimal amino acid profile, we can ensure protein is more efficiently utilized by the cow and, in many cases, this allows us to reduce the amount of dietary protein fed while still maintaining or improving performance,” shares Dr. Sniffen.
Source: Arm & Hammer Animal Nutrition