Effects of agronomic factors on yield and quality of whole corn plants and the impact of feeding high concentrations of corn silage in diets containing distillers grains to finishing cattle1

Abstract

Corn plants were sampled over 2 consecutive years to assess the effects of corn hybrid maturity class, plant population, and harvest time on whole corn plant quality and yield in Nebraska. A finishing experiment evaluated the substitution of corn with corn silage in diets with corn modified distillers grains with solubles (MDGS). The first 2 harvest dates were at the mid- and late-silage harvest times whereas the final harvest was at the grain harvest stage of plant maturity. Whole plant yields increased as harvest time progressed (yr 1 quadratic P < 0.01; yr 2 linear P < 0.01). However, differences in TDN concentration in both years were quite minimal across harvest time, because grain percentage increased but residue NDF in-situ disappearance decreased as harvest time was delayed. In the finishing experiment, as corn silage inclusion increased from 15 to 55% (DM basis) by replacing dry rolled and high moisture corn grain with corn silage in diets containing 40% MDGS, DMI, ADG, and G:F linearly decreased (P ≤ 0.01), with the steers on the 15% corn silage treatment being 1.5%, 5.0%, and 7.7% more efficient than steers on treatments containing 30, 45, and 55% corn silage, respectively. Calculated dietary NEm and NEg decreased linearly as corn silage inclusion increased indicating that net energy values were greater for corn grain than for corn silage. In addition, dressing percentage decreased linearly (P < 0.01) as silage inclusion increased suggesting more fill as silage inclusion increases in diets. Cattle fed greater than 15% corn silage in finishing diets based on corn grain will gain slower and be slightly less efficient and likely require increased days to market at similar carcass fatness and size. When 30% silage was fed with 65% MDGS, DMI, and ADG were decreased (P < 0.01) compared to feeding 30% silage with 40% MDGS suggesting some benefit to including a proportion of corn in the diet. Conversely, when 45% silage was fed with 40% MDGS, ADG, and G:F were greater (P < 0.04) than when 45% silage was fed with just grain implying a greater energy value for MDGS than for corn grain. Substituting corn silage for corn grain in finishing diets decreased ADG and G:F which would increase days to finish to an equal carcass weight; however, in this experiment, increasing corn silage levels with MDGS present reduced carcass fat thickness without significantly decreasing marbling score.

Corn Forage Yield and Quality for Silage in Short Growing Season Areas of the Canadian Prairies

“…In the current study, despite anomalies in some locations, the overall negative correlations between NDFD and DM and starch concentrations, and positive correlations with DMD and NDF concentrations indicate that as the plants matured, NDF concentration declined, but DMD was negatively affected by lower NDFD [42]. This result corroborates the findings of Burken, Nuttelman, Gramkow, McGee, Sudbeck, Gardine, Hoegemeyer, Klopfenstein, and Erickson [27], who reported a decrease of in situ NDF disappearance with progressive maturity. As mentioned by Hunt, Kezar, and Vinande [32] and Johnson, Harrison, Hunt, Shinners, Doggett, and Sapienza [30], selection of high quality silage hybrids should focus on maintaining high grain yields and high fiber digestibility despite advanced stages of maturity.…”

“…Daynard and Hunter [24] observed that CS yield was close to maximum at 300 g kg −1 DM. In more suitable growing areas, Lewis, Cox and Cherney [25] reported a CS yield of 13.6 Mg ha −1 in New York State and Burken et al [27] reported 22.8 Mg ha −1 for Nebraska.…”

Impact of corn silage moisture at harvest on performance of growing steers with supplemental rumen undegradable protein, finishing steer performance, and nutrient digestibility by lambs1

“…Maximum DM yield was achieved when whole-plant DM reached 42% DM, which occurred at the latest date the researchers harvested. Burken et al (2017a) harvested corn plants at three different time points coinciding with traditional silage harvest with a whole-plant DM of 35.8%, physiological maturity with a whole-plant DM of 42.4%, and corn grain harvest. In year 1 of the experiment, stover yield and whole-plant yields responded in a quadratic fashion with both stover and whole-plant yields maximized at physiological maturity and decreased at corn grain harvest.…”

“…Thus, source and amount of supplemental protein are important factors affecting growth because supplemental protein provides a significant amount of the total dietary protein ( Felix et al, 2014 ). When corn silage replaces corn in finishing diets, gain-to-feed ratio (G:F) decreases as corn silage increases in the diet ( Goodrich et al, 1974 ; Burken et al, 2017a ). Management decisions, such as silage harvest maturity, can affect the quality and yield of corn silage and impact performance in growing and finishing cattle ( Chamberlain et al, 1971 ).…”

“…However, as corn silage is harvested later in the harvest season with advanced maturity, whole-plant neutral detergent fiber (NDF) decreases as well as NDF digestibility ( Andrae et al, 2001 ; Owens, 2008 ). Although incorporating distillers grains and corn silage at greater concentrations in growing and finishing diets has been shown to improve animal performance compared to corn silage alone ( Felix et al, 2014 ; Burken et al, 2017a , 2017b ), optimum harvest time to maximize yield and quality and the effects on animal performance have not been evaluated with distillers grains and additional RUP supplementation.…”