Protein digestibility of a feed mixture in a relation to the protein digestibility of the individual protein components

1. Protein digestibility of two proteins was measured when these proteins were given together and separately to rats. 2. The influence of carbohydrates on protein utilization (true protein digestibility, biological value and net protein utilization) was also studied. Autoclaved potato starch was replaced by increasing amounts of glucose, sucrose, fructose and lactose respectively. Glucose, fructose and sucrose appeared to have no specific influence on protein utilization when given in increasing amounts and when compared with autoclaved potato starch. Higher concentrations of lactose, however, caused diarrhoea. 3. The true digestibility of the protein components in a mixture was directly related to the true digestibility of each protein component, including proteins of low digestibility.