Energy and Nutrient Digestibility in Four Sources of Distillers Dried Grains with Solubles Produced from Corn Grown within a Narrow Geographical Area and Fed to Growing Pigs

Two experiments were conducted to determine energy and nutrient digestibility in four sources of distillers dried grains with solubles (DDGS) produced from corn and fed to growing pigs. The objective was to test the hypothesis that energy and nutrient digestibility in DDGS does not vary if samples are procured from ethanol plants that use similar production technologies and use corn that is grown within a narrow geographical area. The four sources of DDGS that were used were procured from ethanol plants that were less than 10 yr old and located within 250 km of each other. In Exp. 1, five growing barrows (initial BW = 71.4 kg) that were fitted with a T-canula in the distal ileum were allotted to a 5x5 Latin square design and used to measure apparent (AID) and standardized (SID) ileal digestibility of AA in the four sources of DDGS. Results of this experiment showed that the SID of CP and all AA except Cys and Pro were greater (p<0.05) in two of the DDGS sources than in the other two sources. Exp. 2 was conducted to measure the concentration of DE and ME and the apparent total tract digestibility (ATTD) of energy, N, P, ether extract, NDF, and ADF in corn and in the same four sources of DDGS as used in Exp. 1. Five pigs (initial BW = 29.7 kg) that were placed in metabolism cages and allotted to a 5x5 Latin square design were used. Results of Exp. 2 showed that the average DE and ME in DDGS were 4,072 and 3,750 kcal/kg DM, respectively, which was less (p<0.01) than the DE and ME in corn (4,181 and 4,103 kcal/kg DM, respectively). The average ATTD for P in DDGS was 56.1%, which was greater (p<0.01) than the ATTD for P in corn (31.9%). The ATTD for ADF in DDGS was also greater (p<0.05) than in corn, but the ATTD for ether extract and NDF were greater (p<0.05) in corn than in DDGS. It is concluded that energy and nutrient digestibility vary among sources of DDGS even when the DDGS is procured from ethanol plants that use corn grown within a narrow geographical region. Thus, factors other than corn growing region are responsible for the variability of energy and nutrient digestibility in DDGS.