Prof. Charles G. Schwab

The adoption of the concept of balancing diets for AA continues to increase in the United Sates.  However, the increase in the rate of implementation, as measured largely by sales of protected Met, has been tied largely to differences in milk prices and feed costs with adoption being slowest when feed costs are high and prices for milk and milk protein are lower.  However, it has been my experience that even when milk prices have been at their lowest long term financial benefits could be realized by balancing for AA.

The Cornell Net Carbohydrate Protein System (CNCPS) and CPM-Dairy were the first two models available to balance rations for AA.  The publication of NRC (2001) and the release of the accompanying model gave an additional interest in formulating dairy diets not only to meet the conventional “protein” requirements of RDP and RUP but also to balance rations for at least the first two limiting AA – Lys and Met.  The rigorous approach adopted in developing the AA supply sub-model in NRC (2001) and the accompanying requirement recommendations for Lys and Met solidified the principles of “ideal protein” into a robust system that works. Dairy diets can now be formulated to ensure a more efficient use of dietary protein while optimizing milk yield and components – particularly milk protein.  This in itself presents the producer with the opportunity to increase income-over-feed cost (IOFC) by producing more of a highly valued product for a marginal increase in feed cost.  However, the “hidden” benefits in some cases may be contributing as much, if not more to herd profitability.  Feeding diets balanced for AA have also been shown to play a preventative role for certain metabolic disorders, with positive effects on energy balance and improved reproductive performance.