Metabolizable Energy

Soybean meal (SBM) contributes between 20 and 30% of the metabolizable energy in most poultry diets. Thus, an accurate assessment of its caloric value is essential for accurate feed formulation. While soybean meal has more gross energy than corn (4200 vs. 3900 kcal/kg, respectively, as fed basis), its carbohydrate fraction is poorly digested and absorbed. The ME of soybean meal is thus only between 50 and 60% of its gross energy. The major factor affecting the ME of soybean meal is fiber, usually the presence of differing amounts of soybean hulls. At times, meals of exceptionally poor quality will have appreciable amounts of foreign material. The ME of SBM can be estimated from this equation: ME (kcal/kg) = 2778 - 66 (% crude fiber), assuming a dry matter content of 88%. In solvent-extracted meals, the level of lipid is generally low and its variation does not greatly affect metabolizable energy.

Example: Calculation of the ME of a sample of SBM with 4.8% CF
ME (kcal/kg) = 2778 - 66 (CF) (88% Dry matter)
= 2778 - 66 (4.8)
= 2461

Note: The r2 of the equation is relatively low (0.61), presumably reflecting unaccounted for variations in carbohydrate fractions and residual oil.

  • Metabolizable Energy of Soybean Meal PowerPoint Presentation
  • Soy Products as Energy Sources for Poultry by Nick Dale
    PDF file
    Published in Soy In Animal Nutrition