The Effect of Proteolytic Enzymes on the Utilization of Animal and Plant Proteins by Newborn Pigs and the Response to Predigested Protein

Proteolytic enzyme concentrates have been used in various attempts to improve the digestibility of proteins by newborn animals. Lahrmann (1882) patented a process for predigesting casein with “digestive ferments”. The casein, which was to be incorporated into a milk for babies, was almost completely digested, resulting in the formation of bitter proteoses, peptones and amino acids. Conquest et al. 1938 lowered the curd tension of milk with a pancreatic concentrate and claimed that calves fed this milk retained the curd in their stomachs for a shorter period of time than when normal pasteurized milk was fed. Williams and Knodt (1951) reported that papain and pancreatin were deleterious when added to a milk replacement for calves. Feed consumption was low, growth was poor and there was evidence of dehydration and intestinal degeneration. Lewis et al. 1955 claimed that supplementing a soya-protein purified diet for 6-lb. baby pigs with proteolytic enzymes improved weight gains and feed efficiency. The authors recognized that the response obtained may have been due to unrecognized growth factors or to improved amino acid balance. When the protein was predigested with pancreatin, negative results were obtained. The present experiments were undertaken to study the effect of supplemental proteolytic enzymes on the digestion of an animal and plant protein by newborn pigs. The effect of predigestion of the protein on its utilization by baby pigs was also studied. Trial 1. Ten 2-day-old littermate pigs were allotted equally to two groups according to body weight. They were placed in wire-bottomed