An Energy Values for Corn and Soybean Feed Ingredients experiment was conducted to determine the digestibility of energy and the concentrations of DE and ME in two sources of enzyme-treated soybean meal (ESBM-1 and ESBM-2), extruded soybean meal (SBM-EX), soy protein concentrate (SPC), conventional dehulled soybean meal (SBM-CV), conventional 00 expelled rapeseed meal (RS), and in a fermented co-product mixture (FCM) fed to growing pigs. Sixty-four barrows weighing about 20kg were allotted into a randomized complete block design with 8 diets and 8 pigs per diet and fed a corn-based diet or a ration containing corn and the test ingredients. Feces and urine were collected for 5 d after a 5 d adaptation period.
The apparent total track digestibility of gross energy (GE) in corn was not different from SBM-CV, but was greater (P < 0.05) than in the other ingredients. The concentration of digestible energy (DE) in corn, ESBM-1, ESBM-2, SBM-EX, SPC, SBM-CV, RSE, and FCM was 3,864, 4,349, 4,121, 4,432, 4,460, 4,303, 3,793 and 3,610 kcal/kg DM, respectively, with a pooled SEM of 91 kcal/kg. The DE in corn was greater (P <0.05) than in FCM, but less (P < 0.05) than in SBM-EX, SPC, ESBM-1, and SBM-CV. The concentration of metabolizable energy (ME) in corn, ESBM-1, ESBM-2, SBM-EX, SPC, SBM-CV, RSE, and FCM was 3,780, 4,158, 3,782, 4,240, 4,226, 4,044, 3,522, and 3,364 kcal/kg DM, respectively, with a pooled SEM of 135 kcal/kg. The ME of corn (3,780 kcal/kg DM) was less (P < 0.05) than in all soybean products except ESBM-2, but greater (P < 0.05) than in the rapeseed products. It was concluded that there are differences among processed soybean products, with some having greater concentrations of DE and ME than others. The concentrations of DE and ME in all soybean products used in this experiment were greater than in rapeseed expellers and the fermented co-product mixture.