Exogenous enzymes, meal size, and meal frequency: effect on ileal and total tract digestibility of carbohydrates, and energy and fiber degradation in growing pigs fed a wheat-barley grain-based high-fiber diet.

To reduce cost and also utilize locally produced ingredients, pig diets nowadays can include a large proportion of fiber-rich ingredients. Exogenous enzymes can be added to diets to improve their digestibility and limit negative effects of fiber. Usually, when conducting a digestibility trial, pigs are fed only twice a day with a restricted feed intake which is not representative of feeding conditions in a commercial farm. This study aimed to determine the effect of meal size and frequency, and enzyme supplementation on digestibility of a diet rich in fiber in growing pigs and in vitro. The diets were supplemented (Enz) or not with xylanase and phytase, and according to different size and frequency: one treatment was pig receiving two meals per day with five times the maintenance energy requirement (2M), another received the same quantity of feed in eight meals (8M), and the last received an amount close to ad libitum feeding in eight meals (8M+). An in vitro experiment was also conducted to look at degradability of fiber with and without xylanase. The results showed that xylanase allows degradation of fiber and increases digestibility of dry matter, starch, and energy. The number and size of meals have little influence on digestibility.