Nitrogen metabolism of the pig: III.—Utilisation of protein from different sources

Young pigs, initially weighing 20 kg, were given diets containing different protein concentrates. The diets provided similar concentrations of available lysine but different concentrations of total lysine and total protein. The diets produced similar growth rates and efficiencies of food utilisation, but pigs given white‐fishmeal were significantly fatter and retained significantly less nitrogen. It is suggested that a deficiency of protein may have been the factor limiting the rate of protein synthesis in the pigs on the fishmeal diet.