Concentrations of digestible, metabolizable, and net energy in soybean meal produced in different areas of the United States and fed to pigs

An experiment was conducted to determine concentrations of DE, ME, and NE in soybean meal (SBM) produced in different areas of the United States if fed to growing pigs. Twenty-two sources of SBM were procured from crushing facilities located throughout the soybean growing area of the United States. For analysis, crushing plant locations were separated into 4 zones: 1) MI, MN, and SD (n = 4); 2) GA, IN, and OH (n = 6); 3) IA, MO, and NE (n = 7), and 4) IL (n = 5). Dietary treatments included a corn-based diet and 22 diets based on a mixture of corn and each source of SBM. Twenty-three growing barrows (initial BW: 26.4 +/- 1.8 kg) were allotted to a 23 x 8 Youden square design with 23 diets and 8 periods. Pigs were placed in individual metabolism crates that were equipped with a feeder, a cup waterer, slatted floors, and a urine tray. Feces and urine were collected for 5 d after a 7-d adaptation period. The GE was 4,165, 4,209, 4,162, and 4,198 kcal/kg (as-fed) for SBM from Zones 1, 2, 3, and 4, respectively, and the GE in SBM from Zone 2 tended (P = 0.08) to be greater than the GE in SBM from Zones 1 and 3. The apparent total tract digestibility (ATTD) of GE for SBM was not different among zones. The DE and ME were 4,343 and 4,098; 4,319 and 4,117; 4,135 and 3,926; and 4,248 and 4,039 kcal/ kg DM for SBM from Zones 1, 2, 3, and 4, respectively. The DE and ME of SBM from Zones 1 and 2 were greater (P < 0.05) than the DE and ME of SBM from Zone 3, but the DE and ME of SBM from Zone 4 were not different from that of the other zones. Net energy was calculated for each source of SBM using a published prediction equation based on DE, ether extract, starch, CP, and ADF. The NE of SBM from Zones 1 and 2 (2,534 and 2,497 kcal/kg DM) was greater (P < 0.05) than the NE of SBM from Zone 3 (2391 kcal/kg DM), but the NE of SBM from Zone 4 (2448 kcal/kg DM) was not different from the NE of SBM from the other zones. Regardless of growing area, values for DE, ME, and NE of SBM determined in this experiment are greater than values published by NRC (2012) and indicate that DE, ME, and NE values for SBM may be underestimated by NRC (2012). In conclusion, regardless of growing area, GE, DE, ME, and NE were not different for SBM from the northern or eastern growing area or from Illinois, but DE, ME, and NE were less in SBM from the western growing area.