EFFECT OF CONDENSED TANNINS IN HULLS OF FABA BEANS (VICIA-FABA L) ON THE ACTIVITIES OF TRYPSIN (EC-2.4.21.4) AND CHYMOTRYPSIN (EC-2.4.21.1)IN DIGESTA COLLECTED FROM THE SMALL-INTESTINE OF PIGS

The effects of condensed tannins in hulls of faba beans (Vicia faba L. ) on the activities of trypsin (EC 3.4.21.4) and chymotrypsin (EC 3.4. 21.1) in digesta obtained from the small intestine of pigs were studie d. Using four castrated male pigs (mean body weight 83 kg) fitted with both a simple T-cannula in the duodenum and a post-valvular T-cannula at the terminal ileum, two experimental diets were tested in a Latin square design. The low-tannin diet (LT) contained 200 g faba bean hull s (cv. Blandine)/kg with a low content of condensed tannins (< 0.1% ca techin equivalents). The high-tannin diet (HT) contained 200 g faba be an hulls (cv. Alfred)/kg with a content of condensed tannins of 3.5% c atechin equivalents. Spot samples of fresh duodenal digesta were taken daily at fifteen time points between 08.00 and 20.00 hours on four co nsecutive days. Ileal digesta were collected nearly quantitatively on the same days between 08.00 and 20.00 hours over periods of 2 h. Tryps in and chymotrypsin activities in duodenal digesta did not differ betw een treatments at any time point (P > 0.05). In ileal digesta of pigs given diet HT the mean activity of trypsin was reduced (P < 0.05). The activity of chymotrypsin in ileal digesta did not differ between trea tments. Trypsin activity: chymotrypsin activity was somewhat lower in ileal digesta of pigs receiving the HT diet (P < 0.10). The apparent i leal digestibility of crude protein (N x 6.25) was lower for the HT th an for the LT diet (0.614 v. 0.728; P < 0.05). Condensed tannins are p robably responsible for the lower activity of trypsin in ileal digesta of pigs fed on high-tannin faba bean hulls. Various explanations for the absence of effects of condensed tannins on enzyme activity in duod enal digesta are discussed.