ARS | Publication request: Whole corn substitution in steam-flaked corn-based diets with different concentrations of wet distiller's grains plus solubles

Submitted to: Proceeding of Plains Nutrition Council Symposium
Publication Type: Abstract Only
Publication Acceptance Date: March 30, 2011
Publication Date: April 14, 2011
Citation: McDaniel, M.R., Walker, D.A., Taylor, K.M., Elam, N.A., Cole, N.A., Loest, C.A. 2011. Whole corn substitution in steam-flaked corn-based diets with different concentrations of wet distiller's grains plus solubles [abstract]. In: Proceeding of 2011 Plains Nutrition Council Spring Conference, April 14-15, 2011, San Antonio, Texas. p. 101.

Technical Abstract: Substituting steam-flaked corn (SFC) with whole shelled corn (WSC) in finishing diets containing wet distiller's grains with solubles (WDGS) could reduce grain processing costs without affecting feedlot cattle performance, feed conversion, and carcass characteristics. This study used 642 Angus-cross heifers (412 +/- 18 kg initial body weight (BW)) assigned to 36 pens in a randomized complete block design (3 blocks based on initial BW. Treatments (2 x 3 factorial) were 6 finishing diets based on SFC with 0 or 20% WSC replacing SFC, and 0, 15, or 30% WDGS replacing SFC (dry matter (DM) basis). Diets were formulated to contain equal concentrations of RDP and fat, and were fed to heifers for 108 d. No WSC x WDGS interactions (P >/= 0.08) occurred for dry matter intake (DMI), average daily gain (ADG), G:F (feed to gain ratio), and carcass characteristics. Heifers fed diets containing 20 vs 0% WSC had greater (P < 0.01) DMI, but final BW, ADG, and G:F were not affected (P >/= 0.11). The percentage of carcasses grading USDA Choice or better tended to be lower (P = 0.07), and the percentage grading USDA Select were higher (P = 0.03) for cattle fed diets with 20 vs 0% WSC. Other carcass characteristics were not affected (P >/= 0.20) by WSC. Increasing WDGS in SFC diets decreased final BW (linear, P < 0.01), tended to decrease ADG (linear, P = 0.10), tended to increase DMI (linear, P = 0.08), and decreased G:F (linear, P = 0.01). Addition of WDGS to SFC diets tended to decrease HCW (linear, P = 0.09), but other carcass characteristics were not affected (P >/= 0.18). In summary, substituting SFC with 20% WSC in finishing diets did not affect animal performance and feed conversion, but decreased carcass quality. In contrast, substituting SFC in finishing diets with increasing amounts of WDGS decreased animal performance and feed conversion, but did not affect carcass characteristics. Limited responses to the substitution of 20% WSC could in part explain the lack of WSC X WDGS interactions. Thus, it is not clear if grain processing could be reduced in finishing diets containing WDGS without affecting feedlot cattle performance and feed conversion.