Predicting dietary amino acid adequacy for ruminants.

Prediction of dietary amino acid balances within the structure of the Cornell Net Carbohydrate and Protein System (CNCPS), as well as predicting amino acid requirements for tissue deposition, and during pregnancy and lactation are discussed. The chapter also elaborates on the prediction of intestinal digestion and excretion, metabolism of absorbed amino acids, as well as the sensitivity of the CNCPS to feed and animal factors, the adjustment of animal and dietary factors to predict actual performance, and possible applications of the CNCPS model. Research needed to improve predictions of amino acid balances involve the models for intestinal amino acid availability, limiting amino acids, amino acid efficiency, and branched-chain amino acid requirements. The discussions in the chapter indicate that it is possible to evaluate ruminant diets for amino acid adequacy and to use this information to make dietary changes that will improve performance.