Dirk B. Burken

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.

Impact of sorting before feeding zilpaterol hydrochloride on feedlot performance and carcass characteristics of yearling steers

Two studies evaluated sorting and feeding zilpaterol hydrochloride (ZH) on feedlot performance and carcass characteristics in randomized block-designed finishing trials. In Exp. 1 (initial BW 342 ± 10 kg, = 1,000), 5 treatments included an unsorted non-ZH fed negative control (-CON), an unsorted ZH fed positive control (+CON), and 3 treatments in which the heaviest 20% within the pen were sorted and marketed 28 d early and the remaining 80% were fed ZH. The 20% were identified at the beginning (EARLY), 100 d from slaughter (MIDDLE), or 50 d from slaughter (LATE). Because of sorting, the remaining steers in sorted treatments were fed 14 d longer than -CON and +CON. Average days on feed for control treatments were 165 and 173 d for the EARLY, MIDDLE, and LATE treatments. In Exp. 2 (initial BW 376 ± 29 kg, = 1,400), 4 treatments included -CON; +CON; an early weight sort fed ZH (1-SORT) with the heaviest 20% identified at d 1 and sorted 50 d from harvest and marketed 14 d before -CON and +CON, with the remaining 80% of the pen fed 7 d longer than -CON and +CON; and a 4-way sort 50 d from harvest fed ZH (4-SORT) with steers sorted into HEAVY, MID-HEAVY, MID-LIGHT, and LIGHT groups marketed -14, 0, +7, and +28 d from -CON and +CON, respectively. Average days on feed for control treatments were 154 and 157 d for the 1-SORT and 159 d for 4-SORT. Steers were fed Zilmax at 8.3 mg/kg DM for 20 d followed by a 3 d withdrawal. In Exp. 1, steers fed +CON had 13 kg greater (P < 0.01) HCW than steers fed -CON. Steers sorted EARLY, MIDDLE, and LATE had 28, 25, and 24 kg heavier ( P< 0.01) HCW than -CON steers, respectively. Carcass weight SD was greater (P = 0.01) for +CON than -CON but was not different (P = 0.17) between -CON and ZH sorted treatments. Percentage of overweight carcasses (454 kg) was greater (P ≤ 0.05) in sorted treatments than in -CON. In Exp. 2, HCW for +CON was 15 kg heavier (P < 0.01) than that for -CON, and HCW for 4-SORT was greater (P < 0.02) than that for +CON. Carcass weight SD was not different (P > 0.10) between +CON and -CON, whereas carcass weight SD of 4-SORT was reduced (P < 0.01) compared with that of -CON and +CON. Steers fed ZH had a greater percentage of carcasses over 454 kg than steers fed -CON (P < 0.01). Although not statistically different (P = 0.27), the percentage of carcasses over 454 kg was reduced by 28% for 4-SORT compared with +CON. Feeding ZH increases carcass weight, but sorting reduces variation, allowing further increases in carcass weight while minimizing overweight carcasses.

Effects of twenty percent alkaline-treated corn stover without or with yucca extract on performance and nutrient mass balance of finishing steers fed modified distillers grains-based diets.

Two experiments were conducted with 192 steers each (during the winter [November to May] or summer [June to October]) to evaluate 3 diets with or without Yucca schidigera extract in a 3 × 2 factorial on steer growth performance and N mass balance. One factor was diet (DM basis): 1) 5% untreated corn stover, 51% corn, and 40% modified distillers grains plus solubles (MDGS; CON); 2) 20% calcium oxide-treated corn stover (CaO added at 5% of stover DM), 40% MDGS, and 36% corn (TRT); or 3) 20% untreated corn stover, 40% MDGS, and 36% corn (NONTRT). The other factor was dietary extract at 0 (NOYE) or 1.0 g/d per steer (YE). No interaction between diet and YE was detected (P > 0.51) for growth performance and carcass traits in winter and only for DMI in summer. Final BW, ADG, DMI, or G:F were not different (P ≥ 0.28) between cattle fed CON and TRT, whereas cattle fed NONTRT had lesser ADG, HCW, and G:F compared to CON and TRT in the winter experiment. During the summer, final BW and ADG tended to be greater (P ≥ 0.07) for CON compared to TRT. Cattle fed TRT had reduced (P < 0.01) G:F compared to CON. No difference was observed (P ≥ 0.36) between YE and NOYE in the winter experiment for performance or carcass traits. In the summer, cattle fed YE had greater (P < 0.02) HCW, ADG, and DMI compared to NOYE. In the summer experiment, cattle fed YE had greater (P < 0.01) N intake, N excretion, and amount of N lost (kg/steer) compared to NOYE, but no difference (P = 0.33) was observed for percentage of N volatilized (% of excretion). Diet had no effect (P > 0.18) on amount (kg/steer) or percentage of N volatized in the winter or summer. All diets had similar amounts (P > 0.13) of DM and OM removed from the pen surface in both summer and winter. Feeding CaO-treated corn stover as a partial grain replacement had no impact on performance in winter but decreased G:F in summer. Although high-fiber diets increased the amount of OM on pen surfaces, they did not impact N volatilized. Feeding a Y. schidigera extract did not affect N balance or manure characteristics.

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 cattle

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.

Finishing performance and diet digestibility for feedlot steers fed corn distillers grains plus solubles and distillers solubles with and without oil extraction1

Three experiments evaluated the effects of corn oil removal using centrifugation in ethanol plants, on animal performance and digestion characteristics by finishing cattle fed by-products. In Exp. 1, 225 crossbred steers (300 ± 9.1 kg) were utilized in a randomized block design with a 2 × 2 + 1 factorial arrangement of treatments. Factors consisted of oil concentration [de-oiled (DO) or full fat (FF)] and by-product type [condensed distillers solubles (CDS) or modified distillers grains plus solubles (MDGS)] compared to a corn-based control. Fat concentration was 6.0% for DO CDS, 21.1% for FF CDS, 9.2% for DO MDGS, and 11.8% for FF MDGS. No oil concentration by by-product type interactions (P ≥ 0.17) were observed. There were no differences in DMI, ADG, or G:F between DO and FF CDS (P ≥ 0.29) or DO and FF MDGS (P ≥ 0.58). No differences (P ≥ 0.25) due to oil concentration were observed for carcass characteristics. Experiment 2 was a 5 × 5 Latin Square digestion trial with treatments similar to Exp. 1. Fat concentration was 8.7% or 15.4% for DO or FF CDS and 9.2% or 12.3% for DO or FF MDGS. Intake and total tract digestibility of fat were greater (P ≤ 0.02) for FF CDS compared with DO CDS. Digestible energy (megacalorie per kilogram), adjusted for intake, was greater (P = 0.02) for steers fed FF CDS compared to DO CDS. Average ruminal pH for cattle fed FF MDGS was greater than DO MDGS (P = 0.06). In Exp. 3, 336 yearling, crossbred steers (352 ± 19 kg) were utilized in a randomized block design with a 2 × 3 + 1 factorial arrangement of treatments. Factors included oil concentration (DO or FF) and inclusion [35%, 50%, and 65% wet distillers grains plus solubles (WDGS)] along with a corn-based control. The fat concentrations of DO and FF WDGS were 7.9% and 12.4%, respectively. A linear interaction (P < 0.01) was observed for DMI, which produced different slopes for DO and FF WDGS. No linear or quadratic interactions were observed for BW, ADG, or G:F (P ≥ 0.31). For the main effect of oil concentration, there were no statistical differences (P > 0.19) for final BW, ADG, or G:F. No statistical differences were observed for all carcass traits (P ≥ 0.34). Corn oil removal via centrifugation had minimal impact on finishing performance suggesting that cattle fed DO by-products will have similar performance to cattle fed FF by-products in dry-rolled and high-moisture corn diets.

Digestibility and performance of steers fed varying inclusions of corn silage and modified distillers grains with solubles to partially replace corn in finishing diets1

Abstract Two finishing and 1 digestibility experiment evaluated the partial substitution of corn with corn silage and corn modified distillers grains with solubles (MDGS). Steers were used in Exp. 1 (n = 295; 467 ± 52 kg) and Exp. 2 (n = 225; BW = 348 ± 27 kg) in a 2 × 2 + 1 factorial arrangement of treatments with factors including corn silage (15 or 45%) and MDGS (20 or 40%) plus a control diet consisting of 5% cornstalks and 40% MDGS. In Exp. 1, there were tendencies for a corn silage × MDGS interaction for ADG, final BW, and G:F (P ≤ 0.08). In the overall F-test for G:F, there were no differences between the control treatment and 15:20, 15:40, or 45:40 (P ≥ 0.15), however, steers fed the control treatment had increased G:F compared to steers fed 45:20 treatment diets (P = 0.03). In Exp. 2, there were no corn silage × MDGS interactions (P ≥ 0.12). As corn silage increased in the diet, ADG, final BW, and G:F decreased (P ≤ 0.01). As MDGS increased from 20 to 40%, ADG and G:F tended to improve (P ≤ 0.07). In the overall F-test, the control was not different for G:F from 15:20, 45:20, or 45:40 (P ≥ 0.15), but had a 4.8% poorer G:F compared to 15:40 (P < 0.01). In Exp. 3, ruminally fistulated steers (n = 6) were used in a 5 × 6 Latin rectangle design and fed 15 or 45% corn silage with 20 or 40% MDGS as a 2 × 2 factorial. An additional diet consisting of 95% corn silage and 5% supplement was fed. There were no corn silage × MDGS interactions for nutrient intake, total tract digestibility, ruminal pH measurements, acetate: propionate ratio (A:P), or in-situ disappearance data (P ≥ 0.31) for the 2 × 2 factorial. As corn silage increased in the diet, DMI, NDF intake, ruminal pH, A:P, in-situ NDF disappearance of corn bran, and DM disappearance of corn increased (P ≤ 0.09) with decreases in DM and OM digestibility (P ≤ 0.03). As MDGS increased in the diet, there was an increase in NDF intake, total volatile fatty acid concentration, and NDF disappearance of corn bran (P ≤ 0.03) with no differences for any other tested variables (P ≥ 0.13). In general, increasing corn silage in place of corn in finishing diets containing MDGS results in a modest reduction in ADG and G:F with increases in ruminal pH.

Evaluation of ractopamine hydrochloride (Optaflexx) on growth performance and carcass characteristics of finishing steers across different feeding durations1

Two experiments were conducted to evaluate the effects of ractopamine hydrochloride (RAC) dose and duration on growth performance and carcass characteristics of finishing steers. In Exp. 1, 336 crossbred steers (initial BW of RAC feeding = 539 kg [SD 22]) were used in a 2 × 2 factorial arrangement of treatments with one factor being RAC dose (0 or 200 mg/steer daily) and the other factor being RAC duration (28 or 42 d prior to harvest). There were no RAC dose × duration interactions ( ≥ 0.08) for growth performance or carcass characteristics. Feeding 200 mg RAC/steer daily increased ( < 0.01) live final BW by 9.0 kg compared with steers not fed RAC. Carcass-adjusted final BW, ADG, and G:F were greater ( < 0.01) for steers fed 200 mg RAC/d compared with steers not fed RAC. Hot carcass weight was 4.7 kg heavier ( < 0.01) for steers fed 200 mg RAC/d compared with steers not fed RAC. In Exp. 2, crossbred steers ( = 576; experiment initial BW = 408 kg [SD 29]) were used in a randomized block design with a 3 × 3 factorial arrangement of treatments. Factors included RAC dose (0, 300, and 400 mg/steer daily) and RAC duration (14, 28, or 42 d prior to harvest). There was a tendency ( ≤ 0.08) for an interaction of RAC dose × duration for final live BW, DMI, and live G:F; therefore, simple effects are presented. At 28 d, live final BW for steers fed 400 mg RAC/d were heavier ( < 0.01) than for steers fed 0 mg RAC/d. There was a tendency at 28 d for increased live final BW for steers fed RAC at 300 mg/d ( = 0.08) compared with steers fed RAC at 0 mg and for steers fed 400 mg RAC/d compared with steers fed 300 mg RAC/d ( = 0.06). Live final BW was greater ( < 0.01) for steers fed RAC for 42 d at 300 and 400 mg/d compared with steers fed 0 mg; however, live final BW was similar ( = 0.48) between steers fed 300 and 400 mg RAC/d. Despite no RAC dose × duration interaction ( = 0.30) for HCW, simple effects will be presented for consistency. Hot carcass weight was greater for steers fed 300 and 400 mg RAC/d for 28 and 42 d compared with steers fed 0 mg at 28 ( ≤ 0.02) and 42 d ( < 0.01). Feeding 300 mg RAC/d for 28 or 42 d increased HCW by 5.1 and 7.6 kg, respectively, compared with steers fed 0 mg RAC. Additionally, feeding 400 mg RAC/d for 28 or 42 d resulted in increases of 8.9 and 9.4 kg, respectively, in HCW compared with steers fed 0 mg RAC. In conclusion, our results confirm that feeding RAC improves growth performance and carcass weight, with an optimal duration of feeding RAC being 28 d.

Use of a complete starter feed in grain adaptation programs for feedlot cattle

Four experiments evaluated the use of a complete starter feed (RAMP; Cargill Corn Milling, Blair, NE) for grain adaptation. In Exp. 1, 229 yearling steers (397 ± 28.4 kg BW) were used to compare a traditional adaptation program (CON) with adapting cattle with RAMP in either a 1- (RAMP-1RS) or 2- (RAMP-2RS) ration system. From d 23 to slaughter, cattle were fed a common finishing diet. In Exp. 2, 390 yearling steers (341 ± 14 kg BW) were used to compare accelerated grain adaptation programs with RAMP with 2 control treatments where RAMP was blended with a finishing diet containing either 25 (CON25) or 47.5% (CON47) Sweet Bran (Cargill Corn Milling) in 4 steps fed over 24 d to adapt cattle. Rapid adaptation treatments involved feeding RAMP for 10 d followed by a blend of RAMP and a 47% Sweet Bran finishing diet to transition cattle with 3 blends fed for 1 d each (3-1d), 2 blends fed for 2 d each (2-2d), or 1 blend fed for 4 d (1-4d). From d 29 to slaughter, all cattle were fed a common finishing diet. In Exp. 3, 300 steer calves (292 ± 21 kg BW) were used to compare the CON47 and 1-4d adaptation programs with directly transitioning cattle from RAMP, which involved feeding RAMP for 10 d and then switching directly to F1 on d 11 (1-STEP). From d 29 until slaughter, F2 was fed to all cattle. In Exp. 4, 7 ruminally fistulated steers (482 ± 49 kg BW) were used in a 35-d trial to compare the CON47 and 1-STEP adaptation programs. Ruminal pH and intake data from the first 6 d of F1and first 6 d of F2 were used to compare adaptation systems. Adaptation with RAMP-1RS and RAMP-2RS increased ( < 0.01) G:F compared with cattle adapted using CON in Exp. 1. Feeding RAMP-1RS increased ADG ( = 0.03) compared with CON. Intakes were similar ( = 0.39) among treatments. Daily gain, DMI, G:F, and carcass traits were similar ( > 0.11) among treatments in Exp. 2. Daily gain, DMI, and G:F were not different ( > 0.20) among treatments on d 39 or over the entire feeding period in Exp. 3. When F1 or F2 was being fed, DMI was similar ( ≥ 0.40) for CON47 and 1-STEP in Exp. 4. When F1 or F2 was being fed, 1-STEP cattle had lower average ruminal pH ( ≤ 0.03) and greater time below a pH of 5.3 ( ≤ 0.03). Using RAMP for grain adaptation improved performance compared with traditional adaptation. Rapid adaptation with RAMP decreased pH, but no performance differences were observed between long and rapid RAMP adaptation programs. Therefore, cattle started on RAMP do not require extensive adaptation before feeding a finishing diet with Sweet Bran.

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