Bryden et al., 2009. June 2009, RIRDC Publication No 09/071

The availability of amino acids in feedstuffs is an important feature of dietary protein quality. Reliable values of this feed ingredient allow more efficient formulation of poultry diets. Many approaches have been made to determine amino acid availability which is defined as that proportion of dietary amino acids that is in a form suitable for digestion, absorption and utilisation. The digestibility assay has become the most favoured technique for estimating availability, largely because the values apply directly to the bird and all amino acids can be measured in the one assay. This RIRDC publication will be a useful resource for the poultry industry, especially nutritionists and those engaged in poultry protein and amino acid research as differences in amino acid digestibility can be effectively used to improve the precision of feed formulation.