Ruminant Nutrition: Dairy--Protein and Amino Acids.

The article presents abstracts of various research papers related to ruminant nutrition, that were presented during the symposium held on July 25, 2005 in Cincinnati, Ohio, which was organized by the American Dairy Science Association, the American Society of Animal Science, and the Canadian Society of Animal Science. In one of the papers titled "A Review of the 2001 dairy Cattle NRC Protein and Amino Acid Model: A European Perspective," NRC 2001 protein and amino acid model was tested using data from eight production experiments with dairy cows conducted using change-over designs. The experiments included a total of 72 selected to represent a wide range in feed intake, milk production and strategies to manipulate metabolizable protein (MP) intake. Grass silage, rolled barley and rapeseed feeds were the most typical forage, energy and protein supplements; that is the test data consisted of diets not typically used in the U.S. It was concluded that the NRC 2001 amino acid model is a significant step forward in achieving a more precise feeding for N. Methodological aspects in determination parameters used to estimate MP supply will be discussed.