Age Dynamics of the Exocrine Pancreatic Function in Broilers as Affected by the Level of Dietary Crude Protein

Abstract

Age dynamics of the pancreatic growth and exocrine function were studied on 90 broilers Smena-9 allotted to three treatments: during the first 14 days of age treatments 1 (control), 2 and 3 were fed diets with 23.0; 21.9 and 24.5% of crude protein (CP), respectively. The pancreas was sampled from the euthanized and decapitated birds at 1, 7, 14, 21, 28 and 35 days of age. Live bodyweight and weight of the pancreas, the activities of the enzymes in the lyophilized homogenate of the pancreas were determined. The activity of amylase was determined by Smith-Roy method (1965), total proteases (TPr) by Batoev method (1971); the activities of trypsin, lipase, alkaline phosphatase (APh) were determined. It was found that the relative weight of the pancreas increased 3.8-fold during the first week of age, then remained relatively constant to 21 days, and then decreased to 28 and 35 days of age. The enzyme-releasing pancreatic activity developed unevenly: activity of trypsin in pancreatic homogenate reached maximum at 7 days of age, lipase at 14 days, amylase and TPr at 28 days; the highest APh activity and APh/TPr index were found at 14 days that was probably related to the intense growth of the pancreas at this age. The activity of TPr at 7 days in treatment 3 was significantly higher by 45.7%, at 28 days by 7.9–22.0% (p < 0.05) in compare to control. These results evidenced that the optimization of the CP levels in commercial diets for broilers requires further research of the age dynamics of protein metabolism .