No abstract

A synthesis of data including over 9,300 head of cattle and over 980 pen means was conducted to evaluate the effect of corn processing method, distillers grains type, oil removal from distillers, and dietary distillers concentration on cattle performance and total feeding costs under different historical price scenarios. The corn processing method was either steam-flaked corn, high-moisture or dry-rolled corn or a blend of the latter two and their effects on performance with and without distillers grains. Wet, modified, and dry distillers were analyzed as either full fat or de-oiled products in diets at various dietary concentrations with either corn type to determine cattle performance. Performance estimates were used to determine the inclusion level that minimized total finishing costs ($/head) for each diet given various assumptions on corn price, corn-to-distillers price ratio, supplemental protein cost, and steam flake processing cost. Feeding distillers grains in steam-flaked or high-moisture and dry-rolled corn diets resulted in improved feed conversion and reduced cattle feeding costs, including lower supplemental protein costs and lower total feeding costs compared with a diet without distillers. However, feeding diets with steam-flaked corn improved feed conversion regardless of distillers type or level of inclusion. Feeding full fat distillers improved feed conversion relative to de-oiled distillers. Cattle fed de-oiled distillers were more efficient than those fed diets containing no distillers grains. At all corn price and corn-to-distillers price ratios examined, feeding some level of distillers of any type produced a lower total feeding costs relative to a diet without distillers. Different robustness tests were conducted to determine the impact of varying steam flake corn processing costs and the cost of supplemental protein on the optimal level of distillers inclusion level. The break-even cost a producer could pay for steam-flaking corn varied but was significantly higher when corn price was high. Feeding distillers grains in steam-flaked or high-moisture and dry-rolled corn diets resulted in improved feed efficiency, reduced cattle feeding costs, including replacement of other supplemental protein and associated costs compared to a diet without distillers grains.

Two experiments were conducted to evaluate the effect of different corn milling methods for high-moisture and dry corn on finishing cattle performance, carcass traits, and nutrient digestion. In experiment 1, steers (N = 600 [60 pens]; initial body weight [BW] = 402 ± 17 kg) were fed for 134 d to evaluate the effect of milling method and corn type on performance and carcass characteristics. Treatments were evaluated as a 2 × 3 factorial design with factors being milling method (Automatic Ag roller mill [ROLL] or hammer mill [HAMMER]) and corn type (high-moisture [HMC], dry [DC], or 50:50 blend of HMC and DC [BLEND]). There were no milling method × corn type interactions for final BW, gain (ADG), or dry matter intake (DMI; P ≥ 0.32), but there tended to be an interaction for G:F (P = 0.09). Cattle fed ROLL HMC had 4.7% greater gain:feed (G:F; P ≤ 0.01) with 55% lower fecal starch (P < 0.01) compared to HAMMER HMC, whereas processing did not impact (P = 0.74) G:F in DC diets. There were no further effects (P ≥ 0.14) on performance or carcass traits regardless of milling method or corn type. In experiment 2, seven ruminally fistulated steers were utilized in a 4 × 7 incomplete Latin rectangle to evaluate the effects of DC or HMC processed with either ROLL or HAMMER (2 × 2 factorial treatment design) on nutrient digestion. Feeding HMC decreased the amount of excreted dry matter (DM) and organic matter (OM; P ≤ 0.01) regardless of mill type, but there was a tendency (P ≤ 0.13) for an interaction between corn type and mill type for DM and OM digestibility. There was no difference between milling treatments fed as HMC (P ≥ 0.69), but the HAMMER DC diet was more digestible than the ROLL DC (P = 0.05). As expected, HMC-based diets had greater (P < 0.01) starch digestibility compared to DC, but milling method had no impact on starch digestibility (P = 0.56). There were no differences (P = 0.56) in average ruminal pH, but HMC diets had greater variance (P = 0.04) and greater area less than pH 5.6 (P = 0.05) compared to DC based diets while milling method did not impact either (P > 0.33). Processing HMC with a roller mill improved G:F compared to processing with a hammer mill, but had little effect when corn was fed as dry corn or HMC:DC blend. Furthermore, feeding cattle HMC compared to DC increases nutrient digestibility, but milling method had little impact.

The objective of this experiment was to evaluate the effect of feeding biochar in a finishing diet on cattle performance, carcass quality, methane (CH4) and carbon dioxide (CO2) emissions. Biochar was sourced from ponderosa pine wood waste (High Plains Biochar, Laramie, WY) and was 83% C with 426 m2/g surface area. Crossbred steers (n = 128; initial BW = 480 kg ± 82 kg) were utilized in a randomized block design (blocked by BW), steers assigned randomly to pen (n = 16), and pen was assigned randomly to treatment. Two treatments were evaluated, a finisher control (CON) without biochar and the same finisher with biochar included at 1.0% of diet dry matter replacing corn (CHAR). Four pen replications per treatment were paired within BW block and rotated randomly through an emissions barn with two chambers (each treatment evaluated simultaneously) to capture average weekly emissions of CH4 and CO2. Pen was experimental unit and chamber was included as a fixed effect for emissions data. Dry matter intake (DMI; P < 0.01) and average daily gain (ADG; P = 0.02) were 2.4 and 5.9% lower for CHAR steers, respectively. Feed efficiency (P = 0.22) and production of CO2 and CH4 (P ≥ 0.60) did not differ between treatments. Methane production was numerically lower for CHAR steers when reported as g per day (1.8% lower) or g per kg of DMI (4.8% lower). Hot carcass weight tended to be lighter (P = 0.10) and calculated USDA yield grade was decreased (P = 0.02) for CHAR steers. There was no difference between treatments for LM area, USDA quality grade, or 12th rib fat (P ≥ 0.12). In conclusion, biochar supplementation at 1.0% of diet DM reduced DMI and ADG and had no effect on CH4 and CO2 emissions in finishing steers.

The objective of this experiment was to evaluate the impact of feeding biochar in a growing diet on cattle performance, methane (CH4) and carbon dioxide (CO2) emissions. Biochar was sourced from ponderosa pine wood waste (High Plains Biochar, Laramie, WY) and was 83% C with 426 m2/g surface area. Crossbred steers (n = 160; initial BW = 357 kg ± 44 kg) were utilized in a randomized block design (blocked by BW), steers assigned randomly to pen (n = 16), and pens assigned randomly to treatment. Two treatments were evaluated, a control (CON) without biochar (40% wheat straw, 40% corn silage, 15% modified distillers grains, 5% supplement) and the same diet with biochar included at 0.8% of diet dry matter replacing corn in the supplement (CHAR). Four pen replications per treatment were paired within BW block and rotated randomly through an emissions barn with two chambers (each treatment evaluated simultaneously) to capture average weekly CH4 and CO2 production. Pen was experimental unit and chamber was included as a fixed effect for emissions data. There were no statistical differences in performance outcomes between CHAR and CON steers (P ≥ 0.23). Numerically, average daily gain (ADG) was greater (P = 0.46) and dry matter intake (DMI) was lower (P = 0.23) for CHAR steers, resulting in a 2.8% improvement in feed efficiency for CHAR steers (P = 0.25). Emissions of CO2 and CH4 did not statistically differ between treatments (P ≥ 0.22). Numerically, CO2 and CH4 emissions were lower for CON compared to CHAR steers when reported as g per day (3.6% lower) or g per kg of DMI (2.4% lower). Based on the results from this study, there was no indication that feeding biochar, supplemented at 0.8% of diet, reduces GHG emissions in growing steers when compared to negative control.