EFFECTS OF SALSEED (SHOREA-ROBUSTA) TANNINS, RESTRICTED FEED-INTAKE AND AGE ON RELATIVE PANCREAS WEIGHT AND ACTIVITY OF DIGESTIVE ENZYMES IN MALE BROILERS

Three groups of 15 male broilers (2 weeks old) were employed as experi mental animals. Two isonitrogenous and isoenergetic diets, one contain ing salseed meal (SSM) and the other containing barley (control) as a major energy source were fed to the birds for 4 weeks. These diets wer e fed ad libitum to the SSM and control groups. In addition, a pair-fe d group was fed the control diet at the same intake level as SSM birds . Blood, digesta, mucosa and pancreas samples were collected by killin g the birds on days 8, 18 and 28 (five birds per group per slaughter d ate). Birds fed the ad libitum control diet utilised their feed more e fficiently than the SSM and pair-fed birds. Pancreas weight of SSM and pair-fed birds were 3.9 and 2.9 g kg(-1) liveweight, respectively, co mpared with 2.4 g kg(-1) liveweight of those fed ad libitum, indicatin g that the presence of tannin in the diet and limited feeding induced an enlargement of the pancreas. However, age had a negative linear eff ect on the relative weight of the pancreas. Unlike trypsin (EC 3.4.21. 4), the activity of alpha-amylase (EC 3.2.1.1) of the birds fed the SS M diet was much lower (81 units g(-1) pancreatic tissue) than that of birds fed the tannin-free diet ad libitum (178 units g(-1) pancreatic tissue). Activities of trypsin and alpha-amylase were markedly lower, 3837 and 186 units g(-1) dry chyme, respectively, in the jejunal diges ta of the birds fed the SSM diet but the linear relationship between t he activities of these enzymes and pancreatic tryptic activity was sig nificant. Lower feed intake also caused a reduction in alpha-amylase a ctivity compared with ad libitum feeding, the activities bring 873 and 1365 units g(-1) dry chyme, respectively. Dipeptidase (EC 3.4.13.11) and disaccharidase activities were significantly depressed in duodenal and jejunal mucosa of the tannin fed birds, the only exception being maltase (EC 3.2.1.20) activity in the jejunal mucosa, which remained u naffected. The linear effect resulted in a gradual increase in the act ivities of these enzymes with age. The only effect for enterokinase (E C 3.4.21.9) was the higher activity (532 units g(-1) mucosa) in the du odenal mucosa of the SSM birds than in birds fed the control diet ad l ibitum (416 units g(-1)). Concentrations of thyroxine were not affecte d by treatment or age. The interactions between treatment and time in all instances were non-significant. (C) 1997 Elsevier Science B.V.