STUDIES CONCERNING THE PROTEOLYTIC CONDIT ION IN THE INTESTINAL-TRACTOF CHICKENS, AS RELATED TO NITROGEN AND PHOSPHORUS UTILIZATION DEPENDENT ON TRYPSIN-INHIBITOR ACTIVITY AND PHYTASE ADDITION IN THE DIET .1.MEASUREMENT OF TRYPSIN ACTIVITY IN PANCREATIC TISSUE AND SMALL-INTESTINE CHYMUS, METHODS AND RESULTS

In a study with 54 broiler chickens (3-4 weeks old), the effects of co rn-soybean diets with limited phosphorus supply (4.2 g/kg) and differe nt trypsin inhibitor activity (6 or 23 TUI/mg dry matter)- partly supp lemented with a phytase, a protease and a purified trypsin inhibitor f rom egg white-on pancreatic mass, trypsin activity in pancreatic tissu e and trypsin activity in small intestinal chymus were investigated. A fter a 12-day feeding period, elevated trypsin inhibitor activity from soybeans in the diet increased pancreatic mass, as well as trypsin ac tivity in pancreatic tissue, significantly. In the small intestinal ch ymus, however, trypsin activity was not increased. The short-term appl iction of a purified inhibitor in the diet decreased trypsin activity in the chymus dramatically with marginal effects on pancreatic mass. C onsequently, different proteolytic conditions in the small intestine w ere achieved. The effects on nitrogen and phosphorus balances, as well as on parameters of phytate hydrolysis under conditions of limited ph osphorus supply, will be discussed in a subsequent publication.