Effects of supplemental β-mannanase on in vitro disappearance of dry matter in feed ingredients for swine

Abstract

The present study was aimed to investigate the effects of supplemental β-mannanase on in vitro ileal disappearance (IVID) and in vitro total tract disappearance (IVTTD) of dry matter (DM) in barley, canola meal, copra meal, corn, corn distillers dried grains with solubles, cottonseed meal, palm kernel meal, soybean meal, and wheat for pigs. Feed ingredient samples were finely ground and divided into the control group and the treatment group. The samples of the control group were prepared to contain 990 g/kg test ingredient and 10 g/kg cornstarch, whereas the samples of the treatment group were prepared to contain 990 g/kg test ingredient and 10 g/kg β-mannanase product (8,000 units/kg in the mixed sample). A 2-step in vitro ileal digestion technique, which simulated the digestion and absorption processes in the stomach and small intestine, was used to determine the IVID of DM in test ingredients, whereas a 3-step in vitro ileal digestion technique, which additionally simulated the digestion process of the large intestine, was used to determine the IVTTD of DM in test ingredients. The in vitro digestion procedures were performed in triplicate for each sample. The addition of β-mannanase increased (p = 0.003) the IVID of DM in wheat and tended to increase (p = 0.063) the IVID of DM in soybean meal. The IVTTD of DM in barley, cottonseed meal, and palm kernel meal was improved (p < 0.05) by the addition of β-mannanase. In conclusion, the digestibility of nutrients for pigs may be improved when β-mannanase is added into diets containing barley, cottonseed meal, palm kernel meal, soybean meal, or wheat.