title: Effects of grind size when alkaline treating corn residue and impact of ratio of alkaline-treated residue and distillers grains on performance of finishing cattle.
abstract: Two studies were conducted to optimize use of alkaline-treated corn stover and wheat straw and distillers grains as partial corn replacements. In Exp. 1, a finishing experiment used 30 pens (12 steers/pen) of calf-fed steers (initial BW = 374 ± 23.9 kg) with a 2 × 2 + 1 factorial arrangement of treatments with 6 replications per treatment. Factors were grind size, where corn stover was processed through a 2.54- or 7.62-cm screen, and chemical treatment (corn stover either fed in native, non-treated form [NT; 93.4% DM] or alkaline treated [AT; 5% CaO hydrated to 50% DM]). No interactions (P ≥ 0.38) were noted between grind size and chemical treatment. Feeding AT compared with NT improved (P ≤ 0.02) final BW, ADG, and G:F. Reducing grind size improved (P ≤ 0.01) ADG and G:F, and no interaction with chemical treatment was observed. Steers fed AT had similar DMI, ADG, G:F, and carcass characteristics compared with a 5% roughage control that contained 15 percentage units (DM basis) more corn. In Exp. 2, 60 individually fed steers (initial BW = 402 ± 61.4 kg) were randomly assigned to 10 diets. Six treatments evaluated 10, 25, or 40% dry-rolled corn (DRC), which was replaced with either a 2:1 or 3:1 ratio (DM basis) of modified distillers grains plus solubles (MDGS) and treated corn stover analyzed as a 2 × 3 factorial. An additional 3 treatments were added where a 3:1 ratio of MDGS:straw were compared with a 3:1 ratio of MDGS:stover. As DRC increased, G:F (P = 0.06) quadratically increased for 3:1 MDGS:stover diets. Increasing DRC increased (P = 0.07) G:F in treated stover diets, regardless of ratio. Increasing DRC increased (P = 0.10) ADG for 3:1 ratios for both straw and stover. Reducing grind size, feeding a maximum of 20% treated crop residue, and maintaining at least 25% corn in the diet are strategies for optimizing cattle performance when replacing dry-rolled and high-moisture corn with treated crop residues and distillers grains.
authors.forename: A L
authors.initials: AL
authors.lastname: Shreck
authors.forename: B L
authors.initials: BL
authors.lastname: Nuttelman
authors.forename: C J
authors.initials: CJ
authors.lastname: Schneider
authors.forename: D B
authors.initials: DB
authors.lastname: Burken
authors.forename: J L
authors.initials: JL
authors.lastname: Harding
authors.forename: G E
authors.initials: GE
authors.lastname: Erickson
authors.forename: T J
authors.initials: TJ
authors.lastname: Klopfenstein
authors.forename: M J
authors.initials: MJ
authors.lastname: Cecava
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D002523:Edible Grain; D005511:Food Handling; D008297:Male; D015430:Weight Gain / Q000187:drug effects*; D003313:Zea mays / Q000737:chemistry*