Effects of a mixture of xylanase and glucanase on digestibility of energy and dietary fiber in corn- or sorghum based diets fed to growing pigs

An experiment was conducted to test the hypothesis that an enzyme premix containing xylanase and glucanase improves the apparent total tract digestibility (ATTD) of energy and total dietary fiber (TDF) and the concentration of digestible energy (DE) and metabolizable energy (ME) in diets fed to growing pigs. A corn-soybean meal diet and a sorghum-soybean meal diet were formulated, and 4 additional diets were formulated by adding 400 g/kg distillers dried grains with solubles (DDGS) or 400 g/kg wheat middlings to the corn-based diet and the sorghum-based diet. Six additional diets were prepared by adding an enzyme premix including xylanase and β-glucanase to each of these diets. One hundred and forty-four growing pigs (61.7 ± 5.3 kg) were allotted to a randomized complete block design with 12 diets and 12 replicate pigs per diet. Pigs were adapted to the diets for 12 days before being moved to metabolism crates. Individual pig weights and feed consumption were recorded, and average daily feed intake (ADFI), average daily gain (ADG), and gain to feed ratio (G:F) were calculated for each dietary treatment. After 4 days of adaptation to the metabolism crates, urine and fecal materials were collected during the following 4 days according to the marker to marker approach. Results indicated that the ATTD of GE, and DE and ME increased (P < 0.01) if enzymes were added to the diets regardless of grain source or co-product inclusion, but no effect of enzymes on ATTD of TDF was observed. However, ATTD of TDF was greater in the corn based diet containing DDGS compared with the diet containing wheat middlings, but in the sorghum-based diet, no difference in ATTD of TDF was observed (grain source × co-product interaction, P < 0.05). However, growth performance were not affected by inclusion of enzymes, but inclusion of co-products to the diets decreased (P < 0.05) the ADG and G:F in pigs. In conclusion, mixture of enzyme including xylanase and β-glucanase used in this experiment has the potential to increase the ATTD of GE, and DE and ME, in both corn-based and sorghum-based diets without or