Porcine in Vitro Digestion and Fermentation Characteristics of Corn Wet Distillers’ Grains and DDGS without or with Multi-Carbohydrase

A study was conducted to determine porcine in vitro digestion and fermentation characteristics of wet distillers’ grains and DDGS without or with multi-carbohydrase (Superyme-CS, Canadian Bio-Systems Inc., Calgary, AB) that supplied 9,600 U of xylanase, 1,200 U of glucanase, 4,000 U of cellulase, 480 U of mannanase, 5,600 U of invertase, 40,000 U of protease, and 96,000 U of amylase/kilogram of feedstuff. Four gram samples were weighed into conical flasks (5 flasks per treatment) and hydrolyzed in 2 steps using pepsin and pancreatin. Similar to the in vivo method of pigs, it is not known if the multi-carbohydrase survived the digestion process. Subsequently, residues were incubated in a buffer solution with minerals and fresh pig feces as inoculum. Gas production was measured for 72 h, and modeled to estimate kinetics of gas production. Concentration of VFA per unit weight of residue incubated or feedstuff was measured in fermented solutions. On DM basis, the wet distillers’ grains and DDGS contained 39.63 and 31.84% CP, and 8.1% and 9.1% ether extract, respectively. In vitro digestibility of DM (IVDDM) of wet distillers’ grains (50.6%) was similar to that of DDGS (48.7%). Multi-carbohydrase supplementation did not affect the IVDDM of wet distillers’ grains or DDGS. Total gas production of residue incubated for wet distillers’ grains was similar to that of   DDGS (108.9 vs. 120.2 mL/g DM). Multi-carbohydrase supplementation tended to increase (P = 0.088) total gas production of residue incubated for DDGS. However, multi-carbohydrase did not affect the total gas production of residue incubated for wet distillers’ grains. Wet distillers’ grains and DDGS were similar in degradation rate of incubated residue. There was no effect of multi-carbohydrase supplementation on degradation rate of incubated residue for wet distillers’ grains or DDGS. Total VFA production of residue incubated for wet distillers’ grains was similar to that of DDGS (6.73 vs. 6.52 mmol/g DM). Also, wet distillers’ grains and DDGS were similar in individual VFA production of incubated residue. Multi-carbohydrase did not affect the total or individual VFA production of residue incubated for wet distillers’ grains or DDGS. In conclusion the wet distillers’ grains were more digestible than DDGS. In conclusion the wet distillers’ grains and DDGS were similar in in vitro digestibility and fermentability. The multi-carbohydrase used in the current study may marginally improve in vitro digestibility of DDGS for pigs.