Energy values of triticale or sorghum distillers’ dried grains with solubles and rye fed to broiler chickens
Abstract The current experiments were conducted to determine ileal digestible energy (IDE), metabolizable energy (ME), and nitrogen-corrected ME (MEn) of triticale distillers’ dried grains with solubles (TDDGS), sorghum distillers’ dried grains with solubles (SDDGS), or rye for broiler chickens using the regression method. Five diets including a corn-soybean meal reference diet and four assay diets, prepared by adding TDDGS or SDDGS at 10% or 20% of the diet to partly replace energy-yielding ingredients in the reference diet, were used. Each of the five diets was fed to eight replicate cages of six birds per replicate cage from day 14 to 21 post-hatching. Similarly in experiment 2, corn-soybean reference diet and two assay diets in which rye at 20% or 40% replaced energy-yielding sources in the reference diet and each of the three diets was fed to eight replicate cages of eight birds per replicate cage from day 18 to 23 post-hatching. Excreta samples were collected twice daily from day 18 to 20 in experiment 1 or day 20 to 22 in experiment 2, and ileal digesta were collected on day 21 (experiment 1) or day 23 (experiment 2). The IDE, ME, and MEn (kcal/kg DM) of TDDGS or SDDGS were derived from the regressions of TDDGS-, SDDGS-, or rye-associated, IDE, apparent ME, and apparent MEn intake in kilocalories against the intake of TDDGS, SDDGS, or rye (X, kg DM), respectively. For diets with TDDGS substitution, regression equations were IDE = 12.3 + 3,288X, ME = −3.0 + 2,800X, and MEn = −0.4 + 2,647X. The equations for the SDDGS diets were IDE = −4.8 + 3,247X, ME = −7.6 + 3,210X, and MEn = −7.0 + 3,072X; and those for the rye diets were IDE = 9.5 + 3,002X, ME = 6.3 + 3,053X, and MEn = 4.8 + 2,928X. The IDE contents did not differ between TDDGS and SDDGS whereas the ME and MEn contents were greater (P < 0.05) in the SDDGS than in the TDDGS. In conclusion, the current study provided energy values of the DDGS sources and rye using the regression method. The regression-derived IDE for TDDGS, SDDGS, or rye were 3,288, 3,247, or 3,002 kcal/kg DM, respectively; corresponding ME were 2,800, 3,210, or 3,053 kcal/kg DM. The respective regression-derived MEn for TDDGS, SDDGS, or rye were 2,647, 3,072, or 2,928 kcal/kg DM for broiler chickens.