Effects of dietary supplementation of xylanase on apparent ileal digestibility of ADF and NDF, and viscosity of digesta in nursery pigs fed corn and soybean meal based diets

Abstract Text: This study was to determine apparent ileal digestibility of ADF and NDF, digesta viscosity, and gut morphology in nursery pigs fed diets containing xylanase (Lohmann Animal Health GmbH, Cuxhaven, Germany). The diet (61% corn, 35% soybean meal, 1% poultry fat, and 3% minerals and vitamins) was mixed with 3 levels of xylanase (0, 700, and 1,400 LXU/kg). Thirty six barrows (17.6 ± 3.3 kg) received one of 3 treatment diets based on a randomized complete block design with the initial BW as a block. Pigs were individually housed and received experimental diets twice daily (0800 and 1700 h) at a fixed amount based on BW of pigs (0.09 x BW^0.75 kg). Pigs were fed diets for 10 d and chromium oxide (0.3%) was added to the diets from d 6 as an indigestible external marker. Pigs were euthanized at the end of d 10 for the collection of digesta and tissues. Jejunal digesta were centrifuged to measure viscosity using a viscometer (Brookfield Engineering Laboratories, Stoughton, MA). Diets and freeze dried ileal digesta were used to measure ADF, NDF, and chromium to calculate apparent ileal digestibility of ADF and NDF. Villus height and crypt depth of jejunum were measured using a microscope (Fisher Scientific, Hampton, NH). Data were analyzed using polynomial contrasts in the MIXED procedure of SAS Software (Cary, NC). Morphological measurements and ileal ADF digestibility were not affected by increasing xylanase. However, increasing xylanase supplementation from 0 to 1,400 LXU/kg enhanced (P <  0.05, linear) ileal NDF digestibility from 27.9 to 40.3% and decreased (P< 0.05) viscosity of jejunal digesta in a quadratic manner from 2.9 to 2.5 centiposes.  In conclusion, the usage of xylanase in corn and soybean meal based pig diets enhanced utilization of NDF  and  affected viscosity of digesta.

Keywords: NDF, pigs, viscosity, xylanase