Estimation of protein digestibility—II. In vitro assay of protein in salmonid feeds

The in vitro digestibility of protein in various salmonid feeds was determined by pH-stat using enzyme fractions from trout pyloric ceca. Data were compared with in vivo digestibility and growth of fish by linear regression analysis. Results indicated that there were good agreements between the degree of hydrolysis of most feed samples and growth of fish. The pH-stat method is not suited for feed samples that have been partially hydrolyzed during their preparation.