beta-glucanase and xylanase activities in stomach and ileum of growing pigs fed wheat bran based diets with and without enzyme treatment

Pigs were fed diets containing 40% wheat bran incubated with a water: aceti c acid mixture (control C) and a cellulase (Cel-i) or xylanase (Xyl-i) prep aration or with addition of the cellulase (Cel-a) or xylanase (Xyl-a) prepa ration immediately before feeding. Stomach and ileal samples were analysed for xylanase and beta-glucanase activities by a standard method based on re lease of reducing substances and a modified method in which the actual pH o f the sample was used. After feeding Gel-treated diets xylanase and beta-gl ucanase activities were higher in the stomach up to 4 hours after feeding. In the stomach the modified method gave significantly lower xylanase activi ties than the standard method. Ileal xylanase activity was significantly hi gher 2-6 hours after feeding Xyl-treated diets and ileal beta-glucanase act ivity was higher 4-6 hours after feeding Cel-treated diets. In ileal sample s, the modified method gave significantly higher xylanase and lower beta-gl ucanase activities than the standard method. It is concluded that xylanase and beta-glucanase activities can be measured in digesta samples with the m ethods employed and that the added enzymes were largely inactivated between the feedings. Measuring digesta enzyme activities in conditions (pH) simil ar to the ones in the gastrointestinal tract may give a more reliable pictu re of the actual activity of added enzymes.