Evaluation of Diet Adaptation Programs and Supranutritional Dietary Antioxidants for Feedlot Cattle

To evaluate feedlot performance and carcass characteristics of finishing beef steers fed diets containing wet distiller's grains with solubles (WDGS) and supplemented with vitamin E, one hundred ninety-nine steers (370 ± 32 kg) were blocked by BW and randomly assigned to 1 of 4 supplemental vitamin E (VITE) treatment levels (0, 125, 250, and 500 IU.steer-1.day-1) fed for the last 97 d of the feeding period. BW and ADG were not affected by VITE treatments. Carcass adjusted final weights resulted in a linear increase in ADG related to a tendency for a linear increase in carcass adjusted BW with increasing concentration of vitamin E supplementation. Pre-VITE and VITE period DMI were not affected by VITE treatments, but there was a trend for a linear increase in overall DMI with increased dietary vitamin E. No difference occurred in G:F measures using live weight gains, but G:F using carcass adjusted weight gains resulted in a trend for a linear increase with increasing dietary vitamin E. Hot carcass weight tended to increase linearly with increasing concentration of vitamin E. Vitamin E supplementation did not affect measured carcass characteristics. A second experiment compared feedlot performance, carcass characteristics, and intake variation of heifers adapted over 28 d to a 94% concentrate diet with 2 different adaptation programs. One hundred forty-four heifers (343 ± 41 kg; arrival 1) and 154 heifers (309 ± 35 kg; arrival 2) were blocked by BW and randomly assigned to either a two–ration blending (2RB) or traditional step-up (TRAD) grain adaptation program. There was no difference in DMI for any period tested. There was a tendency for 2RB heifers to have increased daily DMI variation during the period of d 0 to 6. Heifers on the 2RB program also had increased DMI variation from d 7 to 13. There were no treatment differences in daily DMI variation for all other periods tested. There were also no treatment differences for pen DMI variation. Daily ME intake for the periods of d 0 to 7, d 8 to 14, d 15 to 21, and d 22 to 28 were not different. The heifers on the TRAD treatment tended to have a greater daily ME intake from d 22 to 28. Daily ME intake for d 0 to 35 was not different. Body weight, ADG, and G:F data were not affected by grain adaptation program. Percentage of cattle grading USDA Prime, Choice, Select, or not graded did not differ, nor did percentage USDA Yield Grade 1, 2, 3, or 4. There was an increase in percentage of Choice- carcasses based on marbling score for the TRAD treatment along with a tendency for a lower proportion of carcasses not graded. Calculated yield grade did not differ between treatments.Department of Animal Scienc

Feeding Elevated Levels of Corn Silage and MDGS in Finishing Diets

A finishing experiment evaluated substitution of corn silage and modified distillers grains with solubles (MDGS) in place of corn. The experimental arrangementwas a 2 X 2 + 1 factorial with diets containing 15 or 45% corn silage and 20 or 40% MDGS as well as a control containing 5% cornstalks and 40% MDGS. There were no interactions between corn silage and MDGS inclusion for carcass adjusted performance. As corn silage inclusion increased in the diet, there was a modest reduction in ADG and an increase in F:G. When MDGS inclusion was increased, ADG and F:G were improved. Cattle fed 40% MDGS with 15% corn silage instead of 5% cornstalks had 5% improved F:G

Effect of Distillers Grains Plus Solubles and Monensin Supplementation on Grazing Steers

Yearling steers rotationally grazing smooth bromegrass were individually supplemented monensin at 0 or 200 mg with modified distillers grains plus solubles (MDGS) at .05, 0.4, 0.6, and 0.8% BW. Cannulated steers continuously grazing smooth bromegrass were assigned randomly to one of two treatments: 0.4% BW MDGS supplementation with 0 or 200 mg monensin. Monensin did not affect ADG of steers supplemented MDGS ≥ 0.4% BW. Steers supplemented with monensin had a decreasein estimated average forage intakefrom 16.16 lb to 14.75 lb/OM daily

Effects of increasing soybean hulls in finishing diets with wet or modified distillers grains plus solubles on performance and carcass characteristics of beef steers

Two experiments evaluated feeding soybean hulls (SBH) in finishing diets that contain distillers grains plus solubles on performance and carcass characteristics. Dietary concentrations of SBH were 0, 12.5, 25, and 37.5% of diet DM. In Exp. 1, 167 crossbred yearling steers (395 ± 22 kg of BW) were fed for 117 d in a randomized block design in which pelleted SBH replaced dry-rolled corn. All diets contained 25% modified distillers grains plus solubles, 15% corn silage, and 5% liquid supplement. As SBH concentration increased, DMI decreased linearly (P = 0.04). Gain and G:F decreased linearly (P \u3c 0.01) in response to increasing concentrations of SBH, which decreased relative energy value from 91 to 79% of corn. Hot carcass weight linearly decreased (P \u3c 0.01) by 24 kg as SBH increased. In Exp. 2, a randomized block design used 160 backgrounded steer calves (363 ± 16 kg of BW) in a 138-d finishing study with 0, 12.5, 25, or 37.5% SBH in the meal form. Basal ingredients consisted of a 1:1 ratio of high-moisture corn and dry-rolled corn, 40% wet distillers grains plus solubles, 8% sorghum silage, and 4% dry meal supplement. There was a tendency (P = 0.12) for a quadratic increase in ADG and G:F as dietary SBH increased, with numerically greatest ADG and G:F with 12.5% SBH. Feeding 12.5 to 25% SBH with 40% wet distillers grains plus solubles (Exp. 2) had little effect on performance but decreased ADG and G:F in diets with 25% modified distillers grains plus solubles (Exp. 1)

Comparison of Commercial Lick Tubs to Distillers Grains Supplementation for Calves Grazing Corn Residue

Steer calves grazing irrigated corn residue were supplemented dried distillers grains plus solubles (DGS) or allowedcontinuous access to a commercial lick tub. Dried DGS was fed at 2.94 lb/steer/day and the lick tubs were consumed at 2.04 lb/steer/day (DM basis). Gain was greater for cattle supplemented with dried DGS (1.36 lb/day) compared to those with access to lick tubs (0.83 lb/day). Supplement efficiency varied between calves receiving dried DGS (46%) and those with continuous access to the lick tub (43%) when expressed on a DM basis. Values for dried DGS supplementation (48%) were not different for supplement efficiencyon an OM basis when compared to cattle on the lick tub treatment (50%). Economic analysis shows that as the price of DGS increases, the difference in profit between supplementation strategiesis reduced

Association of Inactive Myostatin in Piedmontese-Influenced Steers and Heifers on Performance and Carcass Traits at Different Endpoints

Performance and carcass traits were evaluated using Piedmontese-influenced calf-fed steers and yearling heifers genotyped for zero, one, or two copies (homozygous active, heterozygous, or homozygous inactive, respectively) of the inactive myostatin allele. Steers and heifers had similar responses across genotypes in performance and carcass traits evaluated at different endpoints. Inactive myostatin decreased DMI, final BW (live), and ADG (live). Increased dressing percentage resulted in increased carcass-adjusted ADG and improved feed conversion for cattle with inactive myostatin. Cattle with inactive myostatin are leaner with larger LM area when finished to equal carcass weight

New approaches to corn silage use in beef cattle finishing diets

Cattle feeders are considering alternative feedstuffs to replace expensive corn grain and decrease rations costs. Feeding corn silage allows cattle feeders to take advantage of the entire corn plant at a time of maximum quality and tonnage as well as secure substantial quantities of roughage and grain inventory. Distiller’s grains have proven to be economical and are now a commonplace ingredient in feedlot finishing diets. Experiments were conducted to determine the effects of feeding increased concentrations of corn silage in replacement of corn grain in finishing diets containing distillers grains. Feedlot gains and gain:feed ratios were reduced as corn silage increased in the diet. Total tract dry matter digestibility of diets containing 45% corn silage was decreased compared to diets containing 15% corn silage. Although total tract neutral detergent fiber (NDF) concentration was not different across corn silage inclusions, in-situ NDF disappearance of corn bran was greater for diets with increased corn silage inclusion. Whole corn plants were sampled and analyzed for two consecutive years for determination of the effects on whole corn plant yield and quality measurements due to hybrid season length, planting density, and whole plant harvest timing. As whole plants were harvested later in the season, yield increased with minimal changes in whole plant quality measures. The economic factors involved in pricing corn silage were assessed, and different economic scenarios were developed for feeding corn silage in finishing diets containing distillers grains. Feeding increased concentrations of corn silage in finishing diets containing distillers grains was determined economical when corn grain price was above $163.38 per metric tonne. As well, as corn grain price and the inclusion of corn silage in the diet increased, reducing corn silage shrink and harvesting corn silage at higher DM contents became more economically beneficial. These data demonstrate that corn silage can economically replace corn grain in finishing diets containing distillers grains. Adviser: Galen E. Erickso

Rapidly Transitioning Cattle to a Finishing Diet with RAMP®

Cattle were transitioned from RAMP to a finishing diet over 27 or 28 days by decreasing RAMP (100 to 0%) and increasing finisher (0 to 100%) gradually over 4 steps or rapidly in fewer days and with fewer steps. Following adaptation, cattle were fed a common diet until slaughter. Grain adaptation treatment did not affect performance or carcass characteristics. Cattle can transition from RAMP to a finishing ration containing 47.5% Sweet Bran® in fewer days with fewer step diets without negatively affecting performance compared to more gradual transition from RAMP to a finishing diet

Effect of Pelleted Byproducts on Performance When Fed to Growing Cattle

Heifers fed a basal diet of either low or high quality forage were supplemented with a corn residue and corn by- product pellet at 0, 0.5, or 1.0% of BW. A linear increase in final BW, ADG, and feed efficiency was observed as supplement increased for heifers fed high quality forage while a quadratic response was observed for those fed low quality forage. Increasing supplement linearly decreased daily average forage dry matter intake from 16.5 lb to 12.6 lb at 0 and 1.0% of BW, respectively. Accordingly, as supplement intake increased, total dry matter intake increased linearly from 16.5 lb to 19.5 lb at 0 and 1.0% of BW, respectively

Transitioning Cattle from RAMP® to a Finishing Diet With or Without an Adaptation Period

Cattle were transitioned from RAMP to a finishing diet gradually over 28 days by decreasing RAMP (100 to 0%) and increasing finisher (0 to 100%) gradually over 4 steps, rapidly in 2 steps or abruptly without an adaptation step. Following adaptation, cattle were fed a common finishing diet for the remainder of the feeding period. Transitioning cattle from RAMP to a finishing diet in 2 steps or without an intermediate step did not affect performance or carcass characteristics compared to a more traditional 4-step program. Cattle transitioned directly from RAMP to a finishing ration had greater among day intake variation and lower DMI after the abrupt transition but had less DMI variation following a transition to final finishing diet. Cattle fed RAMP for 10 days can be transitioned to a finishing ration containing 47.5% Sweet Bran® abruptly without negatively affecting performance