Overcoming the Inhibition of Intestinal Proteolytic Activity Caused by Raw Soybean in Chicks of Different Ages

Abstract
The response of the chicks to transfer from a heated soybean diet (HSD) to a raw soybean diet (RSD) was studied at different ages from one to 6 weeks. The proteolytic activity in the small intestine, nitrogen content of intestinal chyme and pancreas hypertrophy were investigated. An initial inhibition of proteolytic activity was observed at all ages studied. The ability to overcome the inhibition when examined between 1 to 6 weeks generally appears to increase with age. Increase in pancreas weight was noticed after the raw soybean diet had been fed for even one day. Nitrogen content of the chyme was higher in chicks with the RSD than with the HSD indicating an interference of the RSD with normal protein digestion. The study with underprocessed soybean diet showed intermediate results between the HSD and RSD. The probable factors responsible for the rate and length of inhibited proteolytic activity in the small intestine are discussed.