The pancreas is the central digestive organ in both mammals and birds. For a long time (until 1961), the exocrine function of the pancreas in birds was poorly understood. The reason was an anatomical feature, i.e. the connection of three pancreatic ducts and one bile duct into one pappila, which in turn opens into the lumen of the duodenum, which became an obstacle to obtaining a pure pancreatic juice without a bile admixture. For a long time, attempts were made to obtain pure pancreatic juice (Polyakov, 1961; Sosina, 1965; Aliyev, 1970, etc.), but all of them had a number of significant drawbacks. Only the method of Ts.Zh. Batoyev and S. Ts. Batoyeva (1970) based on the implantation of the main pancreatic duct into an isolated segment of the intestine, was successfully used and is still relevant today. The advantage of this technique is that the pancreatic juice is collected only for a short period of time, and is redirected to the intestines for the rest of the time, which contributes to the preservation of bird productivity. The uniqueness of this work is that the authors have studied numerous indicators of birds ’ pancreatic juice, such as the activity of amylase, lipase, protease, total protein, calcium, phosphorus, bile acids, fructosamine, zinc, and copper. Many of these indicators have not been previously studied in birds. The results suggest that the composition of the pancreatic juice of chickens varies greatly after feeding, while the content of calcium and phosphorus, as well as bile acids remains stable. The obtained data are fundamental and can be used further to study the physiology of pancreatic secretion in birds.