Jana L. Harding

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.

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.

Effects of spoilage of wet distillers grains plus solubles when stored in a bunker on nutrient composition and performance of growing and finishing cattle1

ABSTRACT Three experiments evaluated the effect of spoilage of wet distillers grains plus solubles (WDGS) on nutrient composition and cattle performance. In Exp. 1, a 140-d barrel storage study was conducted to simulate bunker storage. An interaction between days of storage and DM, OM, and NDF recovered at the surface in spoiled material was observed. In Exp. 2, a 130-d finishing experiment used 60 individually fed steers fed 3 treatments: a dry-rolled corn–based diet (control) and 2 diets containing 40% WDGS replacing dry-rolled corn. The WDGS was stored in either an uncovered bunker (spoiled) or anaerobically in a silo bag (non-spoiled). Calculations suggest 12% of DM was lost while stored in the bunker. No differences in performance (P ≥ 0.26) were observed between WDGS treatments. However, both WDGS treatments were greater (P ≤ 0.04) in ADG, final BW, and G:F than the dry-rolled-corn diet. In Exp. 3, an 84-d growing experiment used 60 individually fed steers in a 2 × 2 factorial. Treatments were spoiled versus nonspoiled WDGS fed at 15 or 40% (DM basis). Calculations suggest that 6.0% of DM was lost while stored in the bunker. Feeding spoiled WDGS decreased DMI (P