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An experiment was conducted over 2 yr to measure performance and greenhouse gas (GHG) emissions of weaned calves from two cow-calf production systems. Crossbred steers and heifers (n = 270, initial body weight (BW) = 207 kg, SD = 35) were used in a randomized complete block design, with treatments applied to the cow-calf system. Treatments were: 1) a traditional system consisting of April to June calving with smooth bromegrass pasture and grazed corn residue as forage resources (TRAD); 2) an alternative system consisting of July to September calving utilizing partial-drylot feeding, summer-planted oats, and corn residue grazing (ALT). Calves from both production systems were weaned at the same age and grown (diet NEg = 1.05 Mcal kg-1) for approximately 117 d. The calves then transitioned to a high-grain finishing diet (year 1: NEg = 1.32 Mcal kg-1; year 2: NEg = 1.39 Mcal kg-1) and fed to a targeted 1.52 cm backfat. Growth performance in the grower phase resulted in greater (P0.01) average daily gain (1.39 vs. 1.22 ± 0.02 kg), greater gain:feed (P0.01; 0.157 vs. 0.137 ± 0.003) for ALT calves compared to TRAD calves, However, a lower initial BW (P0.01; 185 vs. 229 ± 4.9 kg) resulted in a lower ending BW (P0.01; 347 vs. 371 ± 2.9 kg) for ALT calves compared to TRAD calves in spite of improved growth performance. In the finisher phase, ALT calves gained less (1.52 vs. 1.81 ± 0.218 kg; P = 0.02), were less efficient (0.139 vs. 173 ± 0.0151; P = 0.01) but exhibited similar hot carcass weights (HCW) (388 vs. 381 ± 3.8 kg; P = 0.14) compared to TRAD calves. Each pen of calves was put into a large pen-scale chamber that continuously measured carbon dioxide (CO2) and methane (CH4) for 5 d during the grower and finisher phases. The average CH4 and CO2 production per unit of feed intake was used to calculate total GHG emissions over the entire grower and finisher phase. Overall, there were no differences (P ≥ 0.17) between treatments for CH4 per day and per kilogram dry matter intake (DMI). However, ALT calves tended to produce less (P ≤ 0.10) CO2 per day and per kilogram DMI than TRAD calves. Overall, methane emissions were greater in ALT calves (110.7 vs. 92.2 ± 8.3 g CH4 kg-1 HCW; P = 0.04) than TRAD calves. The ALT calves required 27 additional days on feed to market, which resulted in more total CH4 per animal across the entire feeding period (P = 0.02) than TRAD calves. Production systems that reduce days to market to achieve similar HCW may reduce GHG emissions.There are many reasons (i.e. drought, limited perennial forage, calving) for using intensive or partially intensive production practices (e.g. drylotting or confinement) in a cow-calf enterprise. These practices may impact subsequent calf growth and feedlot performance. In addition, limited data are available comparing the environmental impacts (i.e., greenhouse gas (GHG) emissions) from different cow-calf production systems. This experiment evaluated the effects of a partial-intensive cow-calf production system on post-weaning calf growth performance, carcass characteristics, and GHG emissions. Calves from the partial-intensive cow-calf system had improved growth compared to calves from the extensive cow-calf system during the grower phase. During finishing, calves from the partial-intensive cow-calf system had poorer growth performance resulting in calves from the partial-intensive cow-calf system requiring an additional 27 d on feed to reach finish as calves from the traditional cow-calf system. These differences are likely due to compensation from lower gain periods resulting in better gain in the subsequent growth period. Cow-calf production system did not alter methane and carbon dioxide emissions per kilogram of intake. However, because calves in the partial-intensive cow-calf system required additional days on feed, absolute methane and carbon dioxide emissions were greater per animal for the partial-intensive cow-calf system compared to the extensive cow-calf system suggesting that reducing days to market may reduce emissions from beef systems.

A 2-yr study (year 1: March to September 2017; year 2: February to August 2018) was conducted using crossbred steers (year 1: n = 1677; initial body weight [BW] = 372 kg, SD = 47; year 2: n = 1713; initial BW = 379 kg, SD = 10) in a commercial feedyard study in Eastern NE to determine the effects of shade on cattle performance, ear temperature, and cattle activity. Two treatments were evaluated using a randomized complete block design (n = 5 blocks based on arrival). Treatments were assigned randomly to pens and consisted of five pens without shade (NO SHADE) and five pens with shade (SHADE). Ear temperatures were collected throughout the trials using biometric sensing ear tags on a subset of cattle. Panting scores were collected using a 5 point scale determined visually based on the level of panting occurring on the same subset of steers a minimum of twice weekly from June 8 to August 21 in year 1 and May 29 to July 24 in year 2 by one trained individual each year. In year 1, no differences (P ≥ 0.24) were observed for growth performance or carcass characteristics. Dry matter intake (DMI) and average daily gain (ADG) were greater (P ≤ 0.04) for SHADE cattle in year 2. Over the entire feeding period in year 1, greater (P

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.A pooled analysis of research was conducted to evaluate the effect of corn processing method, distillers grains type, oil removal from distillers, and distillers inclusion on cattle performance within studies conducted at the University of Nebraska-Lincoln between 1992-2020. Two corn processing methods were included in the dataset, steam-flaked corn (SFC) or any combination of high-moisture (HMC) and dry-rolled corn (DRC), fed with and without distillers gains, a by-product of the dry milling ethanol industry. Distillers products were either wet, modified, or dry distillers grains plus solubles and were analyzed as both full fat and de-oiled products. Cattle performance resulting from feeding the six by-product combinations with both corn types was analyzed and then used to find the inclusion level that minimized the total feeding cost ($/head) given different corn prices and corn-to-distillers price ratios. Cattle had improved feed conversion when fed SFC compared with HMC:DRC in all diets. Cattle fed full-fat distillers grains had slightly improved feed conversions compared with de-oiled distillers grains. Cattle fed distillers grains diets had improved feed conversion compared with cattle fed control diets without distillers. Overall, feeding distillers grains in combination with either corn type offers benefits including improved feed conversions, lower finishing costs, and reduced reliance on supplemental protein sources compared to a diet without distillers.

Objective Our objectives were to evaluate nutrient mass balance in feedlots and to determine climactic and management factors affecting nutrient recovery in manure, and to understand sources of variability. Materials and Methods Data from 15 summer- and winter-feeding periods at the Eastern Nebraska Research and Education Center feedlot, including 416 independent pen measurements, were summarized for nutrient mass balance and used to determine sources of variability affecting nitrogen (N) and phosphorus (P) using linear regression. Results and Discussion The quantity of manure N collected was less (P ASABE (2014) standard of 88.5 g/steer daily. Likewise, the quantity of manure P collected for summer was less than winter (P ASABE, 2014 ). The season (summer vs. winter) cattle were fed affected manure nutrient retention and loss. Additionally, feed N intake partially predicted manure N (R2 = 0.22, P Implications and Applications Our analysis identifies challenges associated with planning based on standard methods for estimating manure characteristics. Nutrient composition based on seasonal specific manure analysis is critical. If not available, timing of seasonal feeding period and dietary nutrient concentration may assist with adjusting standardized estimates.

Objective The objective of this survey was to obtain descriptive data and cattle feeders’ perceptions regarding facilities and heat stress (HS) mitigation strategies. Materials and Methods Feedlot managers (n = 46) from South Dakota (SD; n = 21), Minnesota (MN; n = 6), and Nebraska (NE; n = 19) were surveyed regarding facilities, management, and perceptions of HS mitigation strategies. The SD and MN responses were combined (MN/SD) for summarization. Results and Discussion Open yards (OY) were the most commonly reported facility, particularly in NE, where OY were reported by 100% of participants and comprised 90% of facility types. Facility types in MN/SD were more diverse, with OY, total barn confinement, and partially covered comprising 49, 30, and 21% of all facility types, respectively. Shades and sprinklers were used in 79 and 100% of NE OY, respectively, compared with 32 and 86% of MN/SD OY, respectively. Feed deliveries were adjusted in summer by 37 and 30% of NE and MN/SD managers, respectively. All respondents avoided unnecessary cattle handling during HS events. Shades or buildings were perceived as successful by 63 and 56% of respondents from NE and MN/SD, respectively, whereas water application was deemed effective by 32 and 63% from NE and MN/SD, respectively. Shades structures were named by 63% of respondents from both regions as the most desirable HS mitigation measure, followed by confinement buildings (16 and 18% for NE and MN/SD, respectively). Implications and Applications Midwest cattle feeders use multiple approaches to mitigate HS, with those providing shade deemed most desirable.

Three experiments evaluated the effects of three corn silage hybrids, inclusion, and nutrient digestibility in growing and finishing diets. The three hybrids tested included a control (CON), a hybrid containing a brown midrib (bm3) trait (BM3), and an experimental bm3 hybrid with the soft endosperm trait (BM3-SOFT). Experiment 1 utilized 360 crossbred steers (body weight [BW] = 334; SD = 25 kg) to evaluate inclusion of silage in a finishing diet at (15% or 45% of diet dry matter [DM]) and silage hybrid (CON, BM3, or BM3-SOFT). Experiment 2 and 3 utilized 216 crossbred steers (BW = 324; SD = 10 kg) and six ruminally fistulated steers (BW = 274; SD = 27 kg), respectively, to evaluate effects of either CON, BM3, or BM3-SOFT silage hybrids on performance and nutrient digestibility in growing diets. In Exp. 1, there was a silage inclusion × hybrid interaction for average daily gain (ADG) and gain-to-feed ratio (G:F). All treatments with 15% silage had greater (P ≤ 0.04) ADG and G:F compared with 45% silage. Cattle fed BM3-SOFT had greater ADG and G:F than cattle fed CON or BM3 when silage was included at 15% of the diet. When silage was fed at 45% of the diet DM, ADG did not differ between cattle fed either bm3 hybrid. Cattle fed BM3 had the greatest G:F (P < 0.01), with no difference between BM3-SOFT and CON. At 15% silage inclusion, hot carcass weight (HCW) was greater (P < 0.01) for cattle fed BM3-SOFT compared with cattle fed CON and BM3 but did not differ between cattle fed BM3 and CON. At 45% silage inclusion, steers fed either bm3 hybrid did not differ in HCW but were both heavier (P < 0.01) compared with cattle fed CON. In Exp. 2, ending BW, dry matter intake (DMI), and ADG were greater (P < 0.01) for steers fed either bm3 hybrid compared to steers fed the CON, but not different between steers fed the bm3 hybrids. There were no differences (P = 0.26) in G:F between the silage hybrids. In Exp. 3, steers fed either bm3 had greater (P < 0.01) neutral detergent fiber (NDF) and acid detergent fiber (ADF) digestibility than steers fed the CON. Ruminal pH was lower (P < 0.01), and total volatile fatty acid (VFA) concentration was greater (P < 0.01) for steers fed bm3 hybrids compared to steers fed CON. Feeding silage with the bm3 trait improved fiber digestibility, which increased DMI and subsequent ADG in high-forage growing diets. Feeding corn silage with the bm3 trait improved performance compared to non-bm3 corn silage when included above typical roughage concentration.

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 (P0.01) 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 (P0.01) 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 (P0.33). 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.Two experiments tested how processing of corn grain for finishing cattle influences growth performance and nutrient digestion. Producers can use corn in dry or high-moisture form but normally use either a hammer mill or roller mill. When using high-moisture corn, we observed a 5% improvement in gain:feed (G:F) for rolling as compared to hammer milling, which is likely due to more uniform particle size and improved digestion. Unlike the performance study, milling method did not impact digestion for high-moisture corn. Using a hammer-mill for dry corn improved digestion compared to rolling which was not supported by improved performance in the finishing study. Using high-moisture corn increases risk of ruminal acidosis compared to dry corn, but also improves feed efficiency if acidosis can be minimized.

An experiment was conducted to measure production responses of an alternative cow-calf production system integrated into a cropping system without access to perennial forage compared to a traditional cow-calf system utilizing perennial forage. Multiparous, cross-bred beef cows (n = 160; average age = 6.2 ± 2.8 yr) were utilized in a randomized complete block experimental design and unstructured treatment design. Upon initiation, cows were blocked by age and stratified by source, assigned randomly to one of two production systems, each with four replicates (n = 20 cows/replicate). Once allotted to their treatment groups, cows remained in their experimental units for the duration of the experiment. Treatments were: 1) a traditional system consisting of April to May calving with smooth bromegrass pasture and grazed corn residue as forage resources (TRAD); 2) an alternative system consisting of July to August calving utilizing partial-drylot feeding, summer-planted oats, and corn residue grazing (ALT). There were no differences (P ≥ 0.27) in calving rates (91.8 vs. 86.7 ± 2.92%), pregnancy rates (89.3 vs. 89.9 ± 2.66%), and weaning rates (87.2 vs. 82.3 ± 3.29%) for TRAD vs. ALT, respectively. However, there was an increase (P = 0.04) in the rate of twin offspring in ALT (2.9 vs. 9.4 ± 2.36% for TRAD vs. ALT, respectively). One calf from the set of twins was selected randomly at birth to be removed from the experiment, so the production data are only from single calves. There was no difference (P = 0.47) in calf body weight at birth (40 vs. 39 ± 0.7 kg for TRAD vs. ALT, respectively). At weaning, calves in the ALT system were lighter (P < 0.01) at the same day of age (184 vs. 229 ± 5.5 kg) compared to TRAD calves. Cows from the ALT system had fewer (P < 0.01) kg weaned per cow exposed to bull (150 vs. 199 ± 7.2 kg) compared to TRAD cows. Apart from the twinning rate, no differences in reproductive performance were observed among systems. However, reduced weaning weights and kilogram of weaned calf per cow exposed may negatively impact revenue to the cow-calf enterprise of the ALT system.

Feedstuffs utilized in U.S. feedlot finishing rations incorporate high concentrations of N and P, with less than 15% of fed N and P retained by the animal. The remaining N and P are excreted in the manure, where the opportunity for manure N loss via ammonia (NH3) volatilization from the feedlot pen surface is a risk to the environment and lowers the value of manure as a fertilizer. Two nutrient mass balance experiments were conducted during the winter and summer seasons to evaluate the effects of spreading unprocessed Eastern red cedar biochar onto the feedlot pen surface on manure nutrient capture and cattle performance. A 186-d feedlot finishing experiment was conducted from December to June (WINTER) and a subsequent 153-d finishing experiment was conducted from June to November (SUMMER). The WINTER experiment evaluated three treatments (5 pens per treatment; 10 steers per pen), including biochar spread on pen surface during the feeding period (1.40 kg biochar/m2; 17.6 m2/steer soil surface of the pen), hydrated lime spread on pen surface at end of feeding period (1.75 kg/m2) and control (no treatment applied). The SUMMER experiment evaluated biochar treatment (1.40 kg biochar/m2; 5 pens per treatment; 8 steers per pen; and 22 m2/steer soil surface of the pen) against control. There were no differences in N and P intake, retention, or excretion (P ≥ 0.38) between WINTER treatments. Steer performance (P ≥ 0.10) and carcass characteristics (P ≥ 0.50) were not impacted by pen treatment in WINTER. Nitrogen and P intake and excretion (P ≥ 0.35) were not different between treatments in SUMMER and retention of N and P was significantly greater for the biochar treatment (P ≤0.04) due to greater ADG (P = 0.05). There was no difference in DMI (P = 0.48) in SUMMER, steers on biochar pen treatment had heavier HCW (P = 0.05) and greater ADG, resulting in a tendency for greater feed efficiency (P = 0.08). In both experiments, biochar addition to the pen surface tended (P = 0.07) to increase manure N as a percent of manure DM, but this increase in N concentration did not impact kg of N removed from the feedlot pens (P ≥ 0.15) or N losses (P ≥ 0.68). The addition of red cedar biochar to the feedlot pen surface did not increase manure nutrient capture of N or P and did not reduce N losses associated with soil-based feedlot pens.

Feedlot steers (n = 480, initial BW = 389 kg ± 17 kg) were used to test the interaction between corn processing and silage inclusion on the performance and carcass characteristics. Treatments were designed as a 2 × 4 factorial design experiment with factors as 2 corn processing methods (dry-rolled corn, DRC, and steam-flaked corn, SFC) and 4 inclusions of silage (0, 15, 30, 45% of diet DM). Diets also contained 10% MDGS and 5% supplement. Steers were blocked by BW, assigned randomly to pens, and data analyzed using MIXED procedure of SAS with block fixed and pen (n = 48) as the experimental unit. Steers were fed the same days for all treatments (125 d). No significant interactions were observed between corn processing and silage inclusion for performance or carcass characteristics (P > 0.12), therefore, main effects will be presented. As silage inclusion increased, intake (DMI), gain (ADG), and feed efficiency (G:F) changed quadratically (P < 0.03). Gains were greater for cattle fed 15 or 30% silage and lower diets with 0 or 45% silage. Feed efficiency was greatest for steers fed 0% silage (0.168) and decreased to 0.161 and 0.152 as silage inclusion increased to 15 and 30% inclusion. The quadratic response is due to decreased G:F for steers fed 45% silage (0.139). Carcass characteristics responded similar to ADG quadratic (P < 0.01) impacts on fat depth and marbling. Feeding SFC in comparison to DRC led to increased DMI, ADG, G:F, and fat depth (P < 0.04). Gains were greater for cattle fed SFC than cattle fed DRC, which led to increased G:F (SFC = 0.160, DRC = 0.151) across all silage inclusions. Increasing silage inclusion resulted in greater ADG, marbling, and fat depth with 15 and 30% compared with 0 and 45%. Feeding SFC improved performance compared with DRC.

Two nutrient mass balance experiments were conducted during winter and summer seasons to evaluate the effects of spreading unprocessed Eastern red cedar biochar onto the feedlot pen surface on manure nutrient capture and cattle performance. A 186-d feedlot finishing experiment was conducted from December to June (WINTER) and a subsequent 153-d feedlot finishing experiment was conducted from June to November (SUMMER). The WINTER experiment evaluated 3 treatments, including biochar spread to the pen surface during the feeding period (24 kg/steer; 10 steers per pen), hydrated lime spread to pen surface at end of feeding period (31 kg/steer), and control (no treatment applied). The SUMMER experiment evaluated biochar treatment (31 kg/steer; 8 steers per pen) against control. There was no difference in N and P intake, retention, or excretion (P ≥ 0.38) between WINTER treatments. Steer performance (P ≥ 0.10) and carcass characteristics (P ≥ 0.50) were not impacted by pen treatment in WINTER. Nitrogen and P intake and excretion (P ≥ 0.35) were similar between treatments in SUMMER and retention of N and P was significantly greater for the biochar treatment (P = 0.04) due to greater ADG. There was no difference in DMI (P = 0.48) in SUMMER, steers on biochar pen treatment had heavier HCW and increased ADG (P = 0.05), resulting in improved feed efficiency (P = 0.08). In both experiments, biochar addition to the pen surface tended (P = 0.07) to increase manure N as a percent of manure DM, but this increase in N concentration did not impact kg of N removed from the feedlot pens (P ≥ 0.15) or N losses (P ≥ 0.68). The addition of unprocessed red cedar biochar to the feedlot pen surface did not improve manure nutrient capture of N or P and did not reduce N losses associated with soil-based feedlot pens.

Evaluation of new bran products are necessary for continual improvement of wet milling feeds used by the cattle industry. The objective of this study was to evaluate 3 novel corn bran products from Cargill Corn Milling on rumen fermentation and nutrient digestion in beef cattle. Eight ruminally fistulated beef steers were utilized in a 4×4 replicated Latin Square design with 4 dietary treatments and 4 periods (21 d in length for each period with 14 d of adaptation and 7 d of collection). Four treatment diets were bran products (Bran A/B/C) included at 70% of diet dry matter (DM) with 25% steam flaked corn (SFC), and an internal control (SFC control) diet consisted of 70% SFC and 25% Sweet Bran, with 5% wheat straw in all 4 diets. The SFC control exhibited the greatest DM, organic matter (OM) and starch digestibility (P ≤ 0.06), and the least neutral detergent fiber (NDF) digestibility (P < 0.01). When 3 bran products each included at 70%, there was no difference in DM or OM intake and digestibility. Starch and NDF digestibility were greatest (P < 0.01) for bran A fed steers, least for bran C with bran B intermediate. Bran products had minimal effect on energy digestibility, ruminal pH, rumination activity and jugular vein blood parameters. Total ruminal VFAs concentration was greatest (P = 0.04) for SFC control, with no difference among bran A, B and C fed steers. Acetate: Propionate ratio was least (P < 0.01) for SFC control fed steers, greatest for bran A with bran B and C being intermediate. Digestion trait differences existed among different corn bran products, of which feeding bran A resulted in better digestion of starch and NDF, and greater starch content of bran B and C resulted in greater ruminal propionate production.

Steam-flaked corn (SFC) is becoming more common in Northern Plains and Midwest feeding areas. While performance benefits of feeding wet (WDGS) or modified (MDGS) distillers grains are well documented in diets with dry-rolled or high-moisture corn, fewer data are available evaluating distillers grains in SFC-based diets. Therefore, the objective of this study was to evaluate performance when feeding WDGS or MDGS at increasing inclusions in SFC-based finishing diets. Crossbred steers (n = 560; initial BW = 299 kg; SD = 15 kg) were utilized in a 2 × 3 + 1 factorial design with factors consisting of 2 distillers types (MDGS or WDGS) fed at 1 of 3 inclusions (10%, 20%, or 30%) replacing SFC on a dry matter (DM) basis. A 0% distillers treatment was used for determining type by inclusion interactions. An interaction between type and inclusion of distillers was observed for dry matter intake (DMI;P = 0.06) and feed efficiency (G:F; P =0.02). Intake for steers fed WDGS tended to quadratically increase (P = 0.08), while steers fed MDGS had a more dramatic linear increase (P < 0.01) in DMI. Increasing WDGS inclusion resulted in a linear increase in G:F (P = 0.01), whereas increasing MDGS inclusion had no effect on G:F (P = 0.16). No interaction between type and inclusion of distillers grains for other variables (P > 0.20). Feeding distillers grains, regardless of type, resulted in linear increases in daily gain (ADG), hot carcass weight, and backfat (P ≤ 0.03). Control cattle gained 1.73 kg/d while cattle fed 30% MDGS and WDGS had ADG of 1.88 kg/d and 1.90 kg/d, respectively. Overall, gain of calf-fed steers was improved when distillers grains was increased in steam-flaked corn based finishing diets regardless of type, but G:F was increased with WDGS and not MDGS suggesting feeding WDGS provides more energy than MDGS in SFC-based diets.

Two experiments were conducted to evaluate impacts of biochar on methane (CH4) and carbon dioxide (CO2) emissions, performance, and carcass characteristics of finishing beef cattle. Experiment 1 (initial BW = 329 kg ± 19 kg) utilized biochar sourced from pistachio shells (VGrid Energy Systems) in a 70% corn, 20% distillers grains, and 5% corn residue diet. Experiment 2 (initial BW = 386 kg ± 19 kg) utilized biochar sourced from ponderosa pine wood waste (Vital Ag) in a 40% corn, 40% Sweet Bran, and 15% corn silage diet. Both experiments evaluated 2 treatments: control (CON) diet containing no biochar and biochar (BIO) replacing 1% of dietary corn. Pen was the experimental unit with 8 steers per pen and 8 replications. Four replications rotated through a two-chamber emissions barn in 5-d cycles to measure CH4 and CO2 emissions. Cattle performance data were analyzed using the MIXED procedure of SAS with treatment and body weight block as fixed effects and emissions data analyzed as repeated measure. There were no statistical differences in experiment 1 for CH4, g/d (P = 0.75) and g/kg of dry matter intake (DMI; P = 0.99) or CO2 as g/d (P = 0.94) and g/kg DMI (P = 0.88). No impact on cattle performance or carcass characteristics were observed (final BW, DMI, average daily gain, gain to feed, hot carcass weight, longissimus muscle area, USDA quality grade, 12th rib fat; P ≥ 0.21). In experiment 2, there were no statistical differences between treatments for CH4, g/d (P = 0.78) and g/kg DMI (P = 0.84) or CO2, g/d (P = 0.50) and g/kg DMI (P = 0.52). Supplementing biochar at 1% of diet DM did not impact CH4 and CO2 emissions from finishing beef cattle. Cattle performance and carcass characteristics were not impacted by biochar in experiment 1.

Steam-flaked corn (SFC) and high-moisture corn (HMC) offer benefits to the cattle feeding industry including improvement of feed efficiency (G:F) and a guarantee of grain supply, respectively. Popularity of SFC in the Midwest is increasing. A study compared finishing cattle performance when fed HMC, SFC, or blends. The objective was to determine the optimum inclusion of HMC:SFC ratio with or without modified distillers grains (MDGS) included at 20% of the diet. This study utilized 120 yearling steers (352 kg; SD=7.1 kg) individually fed using the Calan gate system in a completely randomized design with cattle stratified by body weight (BW). Treatments included: 100% HMC, 50:50 blend HMC:SFC, or 100% SFC fed with and without 20% MDGS. Additionally, a 25:75 blend and a 75:25 blend of HMC:SFC was fed with MDGS only for a total of 8 treatments (DM basis). Cattle were on feed 140 d with 3-d initial BW and 1 d final BW and carcass weight and characteristics. Animal was the experimental unit with 15 replications per treatment. A tendency for an interaction (P = 0.11) was observed for ADG between distillers inclusion and ratio of HMC:SFC. Cattle fed diets with no distillers grains had improved ADG when fed a blend of HMC:SFC (P = 0.07), but gain was not impacted (P = 0.59) as SFC replaced HMC in diets with 20% MDGS. Feeding MDGS increased carcass weight, ADG, intake, and fat thickness compared with control diets (P ≤ 0.04). For diets containing 5 ratios of HMC:SFC with 20% MDGS, feeding greater inclusions of SFC had no impact on intake or ADG (P ≥ 0.31) but tended to linearly improve G:F (P = 0.09). Overall, including MDGS in HMC, SFC, or blended diets increased carcass weight, ADG, and intake and G:F was improved as SFC increased in diets with MDGS.

Two studies were conducted to evaluate the effect of corn processing method and wet corn gluten feed [Sweet Bran (SB); Cargill] concentration on feedlot performance and nutrient digestion. Treatments were arranged as a 2 × 3 factorial, consisting of two corn processing methods [steam-flaked corn (SFC) or a high-moisture corn (HMC) dry-rolled corn (DRC) blend] and 3 inclusions of SB (0, 20, or 40% of diet dry matter). In Exp. 1, yearling steers (n = 480; initial body weight = 363 ± 15.1 kg) were utilized in a randomized block design. A linear interaction was observed for average daily gain (ADG), feed efficiency (G:F), and hot carcass weight (HCW; P < 0.01). At 0% SB, cattle fed SFC had greater ADG and HCW than cattle fed HMC/DRC. As SB increased, ADG and HCW increased at a greater rate for HMC/DRC cattle than SFC cattle resulting in similar ADG and HCW at 40% SB. At 0% SB, cattle fed SFC were 12.4% more efficient than cattle fed HMC/DRC, but as SB increased the improvement declined to 5.3%. In Exp. 2, 6 fistulated steers were utilized in a 6 × 6 Latin square design. Cattle fed SFC had greater starch digestibility (P < 0.01); HMC/DRC cattle tended to have greater neutral detergent fiber digestibility (P = 0.08). As SB increased, cattle fed SFC and HMC/DRC had greater dry matter intakes (DMI) in both studies (P > 0.01), and as a result, greater digestible energy (DE) intakes (P > 0.01). Increased DE intake improved ADG and G:F when feeding SB in Exp. 1 as explained by greater DMI and increased DE observed in Exp. 2. Feeding up to 40% SB in SFC diets doesn't affect feedlot performance and feeding SB in HMC/DRC based finishing diets linearly improves performance at inclusions up to 40%.

Crossbred, yearling beef steers (n = 210: initial BW = 430 ± 22 kg) were used in a randomized blocked design finishing experiment to evaluate the impact of removing modified distillers grains plus solubles (MDGS) on finishing performance and carcass characteristics. Treatments included feeding 20% MDGS (DM basis) during the entire feeding period (124 d); 20% MDGS until day 79 and then 0% MDGS until the end of the feeding period; or 20% MDGS until day 43 and then 0% MDGS until the end of the feeding period. A total of 21 pens (10 steers/pen) were used with 7 pens/treatment. Cattle were fed a 60:40 blend of high-moisture and dry-rolled corn, with 15% corn silage, 20% MDGS and 5% supplement. Distillers were replaced with the corn blend and urea when removed. Cattle were stepped down to 10% MDGS for 4 days before the complete removal of MDGS. Cattle with MDGS removed on either d 79 or d 43 had reduced (P < 0.05) final BW, DMI, and ADG. Cattle with MDGS removed on d 43 were 5% less efficient (P < 0.05) than cattle fed 20% MDGS throughout the entire feeding period. Cattle fed 20% MDGS throughout the whole feeding had the greatest (P < 0.05) HCW and LM area. There were no differences (P ≥ 0.35) in backfat and marbling scores among treatments, and no differences (P = 0.59) in percent of abscessed livers, although 38% of steers fed 20% MDGS continuously had liver abscesses compared with 46% for steers with MDGS removed on d 43. Based on the results of this study, removing MDGS from finishing diets on either day 43 or day 79 of the feeding period had a negative impact on cattle performance compared with feeding 20% MDGS continuously throughout the entire finishing period.

Three experiments evaluated delaying corn silage harvest, silage concentration, and source of supplemental protein on performance and nutrient digestibility in growing and finishing diets. Experiment 1 used 180 crossbred yearling steers (body weight [BW] = 428; SD = 39 kg) to evaluate corn silage dry matter (DM) (37% or 43%) and replacing corn with silage (15% or 45% of diet DM) in finishing diets containing 40% modified distillers grains with solubles. Experiment 2 used 60 crossbred steers (BW = 271; SD = 32 kg) to evaluate corn silage harvest DM (37% or 43%) and response to rumen undegradable protein (RUP) supplementation (0.5%, 1.4%, 2.4%, 3.3%, or 4.2% of diet DM) in silage growing diets. Experiment 3 used 9 crossbred lambs (BW = 30.1; SD = 4.1 kg) to evaluate nutrient digestibility of 37% or 43% DM corn silage in silage growing diets fed ad libitum or restricted to 1.5% of BW. In experiment 1, as corn silage concentration increased from 15% to 45%, average daily gain (ADG) and gain-to-feed ratio (G:F) decreased (P ≤ 0.04). Carcass-adjusted final BW and hot carcass weight (HCW) were lower (P ≤ 0.04) for steers fed 45% corn silage compared to 15% when fed for equal days. As DM of corn silage was increased from 37% to 43%, no differences (P ≥ 0.30) in dry matter intake (DMI), ADG, G:F, or HCW were observed. In experiment 2, as DM of corn silage increased from 37% to 43%, ADG and G:F decreased (P ≤ 0.04). Increasing supplemental RUP in the diet increased (P ≤ 0.05) ending BW, DMI, ADG, and G:F linearly as supplemental RUP increased from 0.5% to 4.2%. In experiment 3, there were no differences (P ≥ 0.56) in DM digestibility and organic matter digestibility between silage harvest DM and intake level. Neutral detergent fiber (NDF) intake was reduced (P < 0.01) for lambs fed the delayed harvest corn silage compared to earlier corn silage harvest. As silage harvest was delayed from 37% to 43% DM, NDF digestibility decreased (P < 0.01) from 64.39% to 53.41%. Although increasing corn silage concentration in place of corn in finishing diets reduced ADG and G:F, delayed silage harvest did not affect performance of finishing cattle. Delayed silage harvest in growing cattle resulted in lower ADG and G:F, possibly due to increased starch or maturity leading to decreased NDF digestibility. The addition of RUP to silage-based, growing diets improves performance by supplying more metabolizable protein and suggests RUP of corn silage is limiting.

The objectives of these studies were to evaluate the effects of biochar (0%, 0.8%, or 3% of diet dry matter) on diet digestibility and methane and carbon dioxide production from cattle on growing and finishing diets. The growing diet consisted of 21% brome hay, 20% wheat straw, 30% corn silage, 22% wet distillers grains plus solubles, and 7% supplement. The finishing diet consisted of 53% dry-rolled corn, 15% corn silage, 25% wet distillers grains plus solubles, and 7% supplement. In both trials biochar replaced fine ground corn in the supplement. Six crossbred steers (initial body weight [BW] 529 kg; SD = 16 kg) were used in both the growing and finishing trial. The growing diets were evaluated over 6 periods followed by the finishing trial with 3 periods. Digestibility measures were taken over 4 d after at least 8 d of adaptation to diets followed by 2 d of gas emission measurements using headbox calorimeters. Dry matter intake (DMI) was not affected (P ≥ 0.43; 7.91 kg/d) by biochar inclusion in the growing study and increased quadratically (P = 0.07) in the finishing study with 0.8% biochar inclusion having the greatest DMI (12.9 kg/d). Organic matter (OM) and neutral detergent fiber (NDF) digestibility increased quadratically (P = 0.10) in the growing study whereas OM digestibility tended to linearly decrease (P = 0.13) and NDF digestibility was not affected (P ≥ 0.39) by biochar inclusion in the finishing diet. Digestible energy intake (Mcal/d) was not affected (P ≥ 0.25) by biochar inclusion in the growing or finishing study. Methane production (g/d) tended to decrease quadratically (P = 0.14) in the growing study and was decreased 10.7% for the 0.8% biochar treatment relative to the control. There were no statistical differences in methane production (g/d) in the finishing study (P ≥ 0.32) but cattle on the 0.8% biochar treatment produced numerically less (9.6%) methane than the control. Methane production as g/kg DMI of the 0.8% biochar treatment relative to the control was numerically reduced 9.5% and 18.4% in the growing and finishing studies, respectively (P ≥ 0.13). Carbon dioxide production (g/d and g/kg of intake) quadratically decreased (P ≤ 0.06) in the growing study but was not affected by treatment in the finishing study (P ≥ 0.34). Although biochar is not a U.S. Food and Drug Administration -approved feed for cattle, the initial research shows potential as a methane mitigation strategy in both growing and finishing diets.

A 3-yr study evaluated the effects of cow-calf production system and postweaning management on finishing performance and carcass characteristics of calves. Treatments were arranged as a 2 × 2 factorial (1 replication from each of 2 locations each year): (1) cow-calf production system: dry-lot feeding (DL) or grazing corn residue (GRZ) and (2) postweaning management: finishing (FIN) or grow-finishing (GRW). From November to mid-April, DL pairs were fed a distillers and crop residue–based diet in pens and GRZ pairs were supplemented with distillers-based cubes while grazing corn residue. All calves were weaned in mid-April and received into the feedlot for postweaning management. In the FIN treatment, calves were directly adapted to a finishing diet following weaning. Calves in the GRW treatment were placed on a growing diet (30% Sweet Bran, 35% distillers grains, and 35% wheat straw) for 76 d before being adapted to the common finishing diet. Calves from GRZ had lighter BW entering the finishing phase than calves from DL (P

A commercial feedlot study was conducted to compare a combination of inorganic and organic copper and zinc trace minerals (CON) to basic copper chloride and zinc hydroxychloride trace minerals (BCHZ) on performance, carcass characteristics, and incidence of foot rot in feedlot cattle. Crossbred steer calves (n = 1,471, initial BW 273 ± 10 kg) were housed in 16 pens with average head count of 92 steers (71 to 159 steers) per pen. Pens were blocked by origin and assigned randomly to 1 of 2 treatments (8 pens per treatment). Treatments consisted of adding 25 (growing) or 19 (finishing) mg/kg of copper and 136 (growing) or 108 (finishing) mg/kg of zinc to the diet. The CON consisted of copper sulfate and 65% zinc sulfate and 35% zinc methionine, whereas BCHZ consisted of basic copper chloride and zinc hydroxychloride trace minerals. Data were analyzed using the Glimmix procedure of SAS. There was a 4-kg significant difference in initial BW; thus, initial BW was used as a covariate. There were no differences in DMI, ADG, final BW, or G:F (P ≥ 0.14). Hot carcass weight, DP, and USDA QG also were unaffected (P ≥ 0.17) by source of trace mineral supplementation. There were no differences (P ≥ 0.28) in total morbidity or foot rot treatments in terms of total number of pulls or re-treated animals when comparing CON with BCHZ. Cattle that received basic copper chloride and zinc hydroxychloride trace mineral supplement performed similar to cattle that received a conventional mineral program.

Three trials were conducted to evaluate the effect of corn hybrid, kernel traits, growing location, and dry rolling or steam flaking on DM or starch digestibility or both. Trial 1 used 72 commercially available corn hybrids to evaluate the influence of hybrid on kernel characteristics and their effect on digestibility. Kernel characteristics evaluated were test weight, 1,000-kernel weight, and kernel hardness using the Stenvert hardness test. All analyses were conducted on dry, whole corn samples, and DM digestibility was determined for dry-rolled corn samples. Trial 2 used 12 hybrids to evaluate steam flaking or dry rolling on DM and starch digestibility. Flaking and flaking characterization were conducted at the Department of Grain Science and Industry at Kansas State University. Trial 3 used 132 commercially available corn hybrids grown in 3 separate locations to evaluate the effect of growing location, hybrid, and kernel characteristics on DM digestibility. Hybrids evaluated represented a wide range in relative maturity and, therefore, were separated into similar maturity groups for analysis. Results from trial 1 suggest that softer kernels are more digestible than harder kernels. A 27% difference in DM digestibility was found across hybrids when processed as dry-rolled corn. Results from trial 2 show that steam flaking improved DM digestibility (P

The amount of rumen undegradable protein (RUP) in corn silage and the extent to which it is digested in the small intestine are uncertain. Three studies were conducted to determine RUP content of corn silage, and the effects of supplementing increasing concentrations of RUP on the growing performance of calves fed a corn silage diet. Experiments 1 and 2 used in situ methods to evaluate the RUP content of corn silage. In experiment 1, corn silages harvested at 37% or 42% dry matter (DM) were compared. In experiment 2, dry-rolled corn (89.4% DM) was reconstituted to 75%, 70%, 65%, and 50% DM and ensiled in mini-silos (2,265 cm3) for 30, 90, 180, or 270 d to simulate the corn grain within corn silage, dry-rolled corn is more mature than corn grain harvested in corn silage. Experiment 3 used 60 steers (275 kg initial body weight, SD = 18) in an 83-d growing study to evaluate the effects of supplementing 0.4%, 1.7%, 3.0%, 4.2%, or 5.5% RUP (% of diet DM) on performance. In experiment 1, RUP as a % of DM was not different between the two corn silages (P ≥ 0.12), averaging 0.59% for samples refluxed in a neutral detergent solution (NDS) and 1.8% for samples not refluxed in NDS. Dry matter digestibility (DMD) also did not differ (P ≥ 0.19), averaging 67.4%. In experiment 2, as moisture content of the corn grain increased, DMD increased linearly (P < 0.01) and RUP content decreased linearly (P < 0.01). The DMD increased quadratically (P = 0.02), whereas RUP content decreased linearly (P < 0.01) as days of ensiling increased. In experiment 3, there were no differences in DM intake (DMI; P ≥ 0.33) among treatments for period 1 (d 1 to 37). However, average daily gain (ADG) and gain-to-feed ratio (G:F) both linearly increased (P < 0.01) as RUP supplement inclusion increased. There were no differences in DMI (P ≥ 0.16), ADG (P ≥ 0.11), or G:F (P ≥ 0.64) in period 2 (d 38 to 83). For the overall growing period (d 1 to 83), a linear increase was observed for ending body weight (P = 0.01), ADG (P < 0.01), and G:F (P < 0.01) as RUP supplement inclusion increased from 0.4% to 5.5% of diet DM. The RUP content of corn silage is lower than previously reported. Data collected suggest the crude protein within corn silage is 13% RUP, and approximately 1/2 is digestible. The moisture content of corn silage at the time of harvest and the amount of time corn silage is stored continually impact protein availability. Supplementing growing calves fed corn silage with RUP will improve performance.

Cattle naturally respire CO2 from energy and rumen metabolism, and produce enteric CH4 from rumen fermentation. In addition, N2O is produced from soils used for agricultural production following precipitation events. These three gases need to be more accurately quantified in beef production systems to model greenhouse gas (GHG) flux and establish effective mitigation strategies. Most models assume CO2 respiration equals carbon uptake by soil when cattle are fed harvested feeds or during grazing. Therefore, CH4 or N2O release is the net contribution from beef production, while ignoring respired CO2. Recent evidence suggests carbon uptake in soils within grazing systems may offset much of the GHG emissions during beef production. However, total flux is difficult to measure in open, extensive systems including pasture and feedlot pens. Using methods of eddy covariance, footprint modeling, and satellite GPS data on cattle location during grazing, we have estimated CO2 and CH4 production from grazing cattle independent of the pasture (soil and plant) to get accurate fluxes. Regardless of whether the beef industry is already net zero, focus on mitigating enteric methane production is warranted. Three primary methods are used for evaluating CH4: in vitro techniques, calorimetry head boxes, or pen chambers. The most robust system for quantification of enteric methane is pen chambers, which allows for cattle performance to be evaluated simultaneously. Many new additives are being evaluated, but not yet approved for use in food animals. Use of pen-based chambers has a limitation with large numbers of animals that cannot enter the food chain. More focus is required to find suitable methane mitigation strategies from novel feed additives and evaluate changes in productivity and ensuring no residues. Whenever possible, increasing speed of approval for those additives that are effective and pose no risk for food safety will be critical for ruminant production.

One hundred twenty individually fed steers (initial BW 283 kg ± 32) were utilized in an 84-d growing trial to evaluate the effects of increased metabolizable lysine from non-enzymatically browned soybean meal (SoyPass) in grass hay-based diets containing wet distillers grains plus solubles (WDGS). The treatments were arranged as a 2 × 3 factorial with two levels of protein supplement as 20% (low; DL20) or 35% (high; DL35) of dietary DM using WDGS as the basal protein source, and three increments of SoyPass (SP) replacing 0%, 30%, or 60% of the WDGS DM in the protein supplement yielding six dietary treatments. Average daily gain (ADG), dry matter intake (DMI), gain:feed (G:F), and plasma urea N (PUN) data were analyzed using the MIXED procedure of SAS as a 2 × 3 factorial. Animal was the experimental unit and fixed effects included body weight block, dietary inclusion of distillers grains (DL20, DL35), dietary inclusion of SoyPass (SP) (3 levels), and DL × SP inclusion interactions. Linear and quadratic interactions between DL and SP inclusion were analyzed using covariate regression. No interactions were detected for ADG between SP and DL (P = 0.76). Additionally, SP had no effect on ADG (P = 0.49). However, ADG was increased for steers consuming the DL35 diet compared to DL20 (1.13 vs. 0.86 kg/d, respectively; P < 0.01). A DL × SP interaction was detected for DMI (P = 0.01). As SP replaced WDGS in the DL35 diet, DMI increased linearly from 8.10 to 8.93 kg/d (P = 0.02). In the DL20 diet, DMI was not different as SP replaced WDGS (P ≥ 0.11). Therefore, G:F tended to decrease linearly (P = 0.06) as SP replaced WDGS in the DL35 diet, while no difference (P ≥ 0.11) was detected in the DL20 diet, suggesting SP contained less energy than WDGS but did improve dietary lysine balance. Furthermore, plasma urea nitrogen (PUN) increased linearly as SP replaced WDGS in the DL20 diet (P < 0.01) but was not affected by SP substitution in the DL35 diet (P ≥ 0.19). When WDGS is fed at a low (20% DM) or high (35% DM) inclusion rate in a forage-based diet, replacing the distillers with a source of protected amino acids supplied through heat-treated soybean meal, did not improve performance. A more concentrated or energy-dense form of amino acids may be beneficial in forage-based growing cattle diets containing 20% distillers grains but is not needed in diets with 35% distillers grains.

Steers (n=600; Initial BW = 402 ± 17 kg) were fed for134 day to evaluate the effect of milling method and corn type on performance and carcass characteristics. Treatments were evaluated as a 2 × 3 factorial with factors being milling method (Automatic Ag® roller mill or hammer mill) and corn type (100% high-moisture, 100% dry, or 50:50 blend of high-moisture and dry corn). High-moisture corn was processed at harvested based on respective treatment and ensiled until trial initiation. Both dry corn and HMC were processed using a 16-mm screen in the hammer mill and the roller mill was adjusted to ensure all kernels were broken. There were no interactions between milling method and corn type for final BW, daily gain (ADG), or dry matter intake (DMI; P ≥ 0.32), but there was a tendency for an interaction for G:F (P = 0.09). Cattle fed 100% high-moisture corn processed with the Automatic Ag roller mill were 4.7% more efficient (P ≤ 0.01) with 55% lower fecal starch (P < 0.01) compared to high-moisture corn processed with the hammer mill. Cattle fed dry corn tended (P = 0.07) to have a greater live final BW regardless of milling type and had the greatest DMI (P ≤ 0.01) Intake decreased as high-moisture corn was increased in the diet. Due to no differences in ADG with lower DMI led to a 6% improvement (P ≤ 0.01) in G:F for steers fed HMC. There were no further effects (P ≥ 0.14) on performance or carcass traits regardless of milling method or corn type. Processing high-moisture corn using Automatic Ag roller mill improved feed efficiency compared to processing with a hammer mill when corn was included at 70% of the diet, but processing method had little effect when fed as dry corn or blended diets.

Evaluation of corn silage digestibility is normally done using laboratory techniques to predict the performance if fed to cattle, which may or may not predict actual performance when fed to cattle. The objective of this study was to evaluate two Masters Choice corn silage hybrids previously selected for improved fiber and starch digestion on nutrient intake and digestion in cattle. In a 126-day digestion study, six ruminally fistulated beef steers were utilized in a 3×6 Latin rectangle design with three dietary treatments and six periods (21 days in length with 14 days of adaptation and 7 days of collection). Diets consisted of 80% corn silage (dry matter basis) of Masters Choice hybrid MCT6365 RIB (MC1; selected for greater fiber and starch digestion) and MCT6733 GT3000 (MC2; older hybrid selected for greater fiber digestion) and were compared to a conventional corn hybrid (CON; commonly grown in Eastern Nebraska). The remainder of the diet included 15% modified distillers grains plus solubles and 5% supplement. Corn silage hybrid did not impact dry matter or organic matter (OM) intake (P ≥ 0.68), but hybrid treatment impacted OM, starch, and energy digestibility (P < 0.02). Steers fed MC1 corn silage had greater (P < 0.01) total tract OM and energy digestibility, as well as digestible energy (DE, P = 0.02) content of the diet when compared to MC2, with steers fed CON being intermediate (P ≥ 0.09). Feeding MC1 also resulted in greater (P = 0.03) total tract starch digestibility than MC2, with no difference (P = 0.12) when compared to CON. Results indicated that feeding MC1 corn silage improved digestion and energy availability to the steers, which allowed for greater average daily gain and improved feed efficiency observed in the corresponding growing trial, while the opposite was true for MC2.

Six ruminally and duodenally cannulated steers were utilized in a 3 × 3 replicated Latin square experiment to determine duodenal fatty acid (FA) flow. Treatments consisted of 3 levels of Green Grass (GG, Sunseo Omega 3; Chungcheong Duk-Do, South Korea), a feed comprised of sesame meal, giant kelp, cassava, and sorghum, at 0, 15, and 30% of diet DM. Data were analyzed using the MIXED procedure of SAS with treatment and period as fixed effects and animal as a random effect. There were no differences in DMI, organic matter (OM) intake, total tract DM or OM digestibility (P ≥ 0.16). Intake of NDF and ADF increased linearly (P < 0.01) from 0 to 30% GG inclusion. Total tract digestibility of NDF was the poorest (P ≤ 0.02) for GG0 with no differences between GG30 and GG15 (P = 0.33). Total tract ADF digestibility was poorest for GG30 (P < 0.01) while GG0 and GG15 were not different (P = 0.17). Fatty Acid values were reported as relative abundance of the total FA present in duodenal samples. The lowest (P < 0.01) concentration of saturated FA was GG30 (70.3%) while GG0 and GG15 were not different (P = 0.83; 78.2%). The concentration of unsaturated, mono-unsaturated, poly-unsaturated, and trans FA responded quadratically (P < 0.01) with no difference between GG0 and GG15 and increasing to GG30. Omega-6 FA tended to decrease linearly (P = 0.06) from 0 to 30% GG inclusion (4.91 and 3.85 g/d, respectively). Omega-3 FA increased linearly (P < 0.01) from 0 to 30% GG inclusion (1.84 and 10.78 g/d, respectively). These data suggest increasing inclusion of GG up to 30% of diet DM does not affect DM or OM digestibility. Greater inclusions of GG resulted in more unsaturated and omega-3 FA concentrations in the duodenum.

The objective of this study was to evaluate the effects of increasing inclusions of steam-flaked hybrid rye (SFR) replacing steam-flaked corn (SFC) in finishing diets on cattle performance and carcass quality. Rye was grown as one hybrid and processed at a single feedyard in eastern Nebraska (14.5 kg/bu for SFR, 2.55 ± 0.94 mm average particle size). Crossbred yearling steers (n = 400, initial BW = 400 ± 24 kg) were used in a randomized block design (blocked by BW and source), stratified, and assigned randomly to pen (n = 40), and pen assigned randomly to treatment. Four treatments were evaluated, a control with no SFR (0%), and 3 inclusions of SFR where the rye replaced 25%, 50%, or 100% of the SFC in the diet (0%, 15.4%, 30.8%, and 60% SFR respectively). A linear decrease in carcass weight, dry matter intake, average daily gain (ADG), and gain:feed (G:F) was observed as SFR inclusion increased in the diet (P ≤ 0.01). Intake decreased by 1.2 kg/d as SFR increased from 0 to 100% of the grain inclusion. A 14.5% reduction in ADG and 6.2% decrease in G:F was observed as SFR replaced SFC, which lead to decreases in calculated NEm and NEg dietary energy values based on performance. Longissimus muscle area (P ≤ 0.01), 12th rib fat (P ≤ 0.03), and marbling score (P ≤ 0.01) decreased linearly with increasing rye inclusion. Calculated yield grade did not differ among treatments (P = 0.16). These data suggest no evidence of an associative effect for blending SFR with SFC. Based on dietary energy calculated using performance, SFR has approximately 92% the energy value of steam-flaked corn. Feeding flaked rye grain decreased intake, gain and feed efficiency suggesting SFR contains less energy than steam-flaked corn.

A commercial feedlot trial utilizing 870 crossbred heifers (initial BW = 322; SD = 9 kg) examined two implant strategies on growth performance and carcass characteristics. Treatments included: 1) Revalor-IH on d 1 (80 mg trenbalone acetate (TBA)/8 mg estradiol (E2), noncoated) and re-implanted with Revalor-200 on d 101 (200 mg TBA/20 mg E2, noncoated (REV-IH/200); or 2) Revalor-XH on d 1 (200 mg TBA/20 mg E2, partially coated (REV-XH). There were no differences (P > 0.23) observed for live performance including final BW, DMI, ADG, and feed efficiency between implant treatments. There were no differences (P ≥ 0.17) in carcass-adjusted final BW or ADG between implant strategies. There were no differences (P ≥ 0.28) observed for DMI before or after re-implanting for heifers given REV-IH/200 compared to heifers given REV-XH. Heifers implanted with REV-IH/200 had greater carcass-adjusted feed efficiency compared to REV-XH (0.156 vs. 152; P = 0.03). Heifers implanted with REV-IH/200 had larger LM area compared to heifers with REV-XH (88.4 vs. 83.9 cm2; P < 0.01). Calculated yield grade was lower for heifers implanted with REV-IH/200 compared to heifers implanted with REV-XH (3.75 vs. 3.89; P < 0.01). Hot carcass weights, dressing percent, marbling, and 12th rib back fat were not different (P ≥ 0.11) among treatments. Heifers implanted with REV-IH/200 had a shift towards lower USDA yield grade distribution compared to REV-XH implanted heifers (P = 0.05). The REV-IH/200 combination provided 280 mg of TBA and 28 mg E2, while total active ingredient dose for REV-XH was 200 mg TBA and 20 mg E2. Therefore, minimal differences were observed in carcass-adjusted feed efficiency, LM area, and calculated yield grade between REV-IH/200 and the partially coated REV-XH implant.

Economic beef production requires efficient growth. In our herd, cows were identified that exhibited irregular (start-stop) or absent (non-cyclic) pubertal estrous cyclicity prior to their 1st breeding season. These cows were sub-fertile but weaned heavier calves. Here, we determined if these calves possessed enhanced muscling and metabolic efficiency. Early muscle growth and metabolic indicators, feedlot performance, and carcass traits were evaluated in steer calves from cows that had exhibited normal (typical), start-stop, or non-cyclic pubertal estrous patterns. Start-stop and non-cyclic cows calved later (P < 0.05) than typical cows, but calf birthweights did not differ among groups. Weaning weights tended to be decreased (P = 0.09) in calves from start-stop and non-cyclic cows, but 205-d adjusted weaning weights did not differ. At 3 mo, body composition estimated by bioelectrical impedance revealed a tendency for reduced (P = 0.10) muscle mass in calves from non-cyclic and start-stop compared to typical cows. Plasma cholesterol, high-density lipoprotein, and triglyceride concentrations were reduced (P < 0.05) and glucose/insulin tended to be increased (P = 0.09) in calves from non-cyclic cows. Plasma urea nitrogen did not differ among groups. Ex vivo proliferation was greater (P < 0.05) for myoblasts isolated from calves of start-stop and non-cyclic compared to typical cows. Total oxidative metabolism did not differ but glycolysis was decreased (P < 0.05) in myoblasts from calves of non-cyclic cows. Feedlot average daily gain and dry matter intake did not differ during growing or finishing. Feed efficiency tended to be increased (P = 0.09) in calves from non-cyclic cows but not when normalized to dressing percentage. Hot carcass weight, dressing percentage, ribeye area, fat thickness, and marbling did not differ among groups. These findings indicate that atypical maternal estrous cyclicity at puberty reduced early muscle growth and metabolism in offspring but not feedlot growth or carcass merit. We speculate that early growth deficits are influenced by inflammatory changes.

Corn hybrids can be selected for improved digestion rates using lab techniques, which should impact animal performance. The objective of this study was to evaluate two Masters Choice corn silage hybrids on growing steer performance. In an 84-day growing study, 288 crossbred steers (initial BW = 303 ± 12 kg) were utilized in a generalized randomized block design with three diet treatments, 12 steers per pen and 8 pen replicates per treatment. Diets consisted of 80% corn silage (DM basis) of Masters Choice hybrid MCT6365 RIB (MC1, that has been selected to improve fiber and starch digestion) and MCT6733 GT3000 (MC2, that has been selected to improve fiber digestion) were compared to a conventional corn hybrid Farm Choice (CON, that is commonly grown in Eastern Nebraska). All corn was grown in one field under identity preserved method and harvested at 37-38% DM in three consecutive days. Relative to CON, feeding MC1 resulted in similar dry matter intake (DMI, P = 0.28), but numerically increased average daily gain (ADG, P = 0.14) which significantly improved feed efficiency (G:F, P = 0.02). Feeding MC2 led to greater DMI (P < 0.01), similar ADG (P = 0.45), and lower G:F (P < 0.01) compared to CON. The results suggest that feeding Masters Choice hybrid MCT6365 RIB (MC1) corn silage at 80% of the diet DM improved ADG and G:F by 4.2%, while feeding MC2 decreased G:F by increasing DMI compared to CON. Differences in corn hybrids exist when feeding growing cattle 80% silage.

A finishing study used 240 crossbred steers (initial BW=340 ±24 kg) to evaluate performance, carcass characteristics, and fatty acid profiles of beef from finishing steers. Four inclusions (0, 10, 20, 30 % DM basis) of Green Grass displaced dry rolled corn in the finishing diet. Green Grass is a blend of herbs and plants imported from Korea that are high in omega-3 fatty acids with 13.9 % fat,32.0 % CP, and 27.0 % Acid detergent fiber. The remaining diet consisted of 15 % WDGS, 20 % corn silage, and 6 % liquid supplement (DM basis). There were no differences in final BW, gain or carcass traits (P³0.14). Cattle were harvested over three slaughter days and were fed for 190, 199, or 203 days. Dry matter intake linearly increased (P = 0.04)as Green Grass inclusion increased in the diet. A linear response (P£0.01) to feeding Green Grass was observed for G:F, with steers fed Green Grass having lower feed efficiency than control cattle. The G:F of cattle fed Green Grass was 5.4, 3.4, and 6.8 % lower in G:F as inclusion increased suggesting Green Grass has 68.6 % the energy of corn it replaced. Steers fed 30 % Green Grass had a lower marbling score. Linear increases in alpha linolenic acid, trans-unsaturated fatty acids, and omega-3 fatty acids (P£0.01) were observed in steak samples from steers fed increasing inclusion of Green Grass. Including up to 30 % inclusion of Green Grass on a DM basis in finishing diets decreased G:F; however, it appeared to have no other effects on performance or carcass characteristics. Feeding Green Grass linearly improved omega-3 fatty acid concentration in beef.

Elevating corn silage inclusion in finishing diets has been investigated and suggests feeding more silage in farming and feeding operations improves profitability, despite decreased gain (ADG) and feed efficiency (G:F). Feeding more silage may decrease liver abscesses and the need for antibiotic control of abscesses. A finishing study was conducted to assess the impact of silage inclusion in finishing diets to reduce the incidence of liver abscesses in beef cattle. A total of 640 (BW = 334 ± 25 kg) steers were utilized in a 2 × 2 factorial treatment design with two levels of corn silage (15 and 45%, diet DM), with or without tylosin for control of abscesses. This study utilized 32 pens of cattle with 20 steers per pen and 8 pens per treatment. There was an interaction for liver abscesses (P = 0.05) and a tendency for an interaction for performance (P = 0.10) between silage and tylosin inclusion but not for carcass traits (P ≥ 0.20). Cattle fed 15% corn silage had the greatest incidence of liver abscesses (34.5%) compared to other treatments (P = 0.05), and abscess rate was decreased to 19% if tylosin was fed. Feeding 45% silage was also effective at lowering liver abscess rates which were 12.4% regardless of whether an antibiotic was fed. Feeding corn silage at 45% of diet DM was as effective as feeding an antibiotic to cattle on 85% concentrate diets. Feeding corn silage at greater inclusions decreased ADG (P ≤ 0.01) but increased final body weight when fed to an equal fatness. However, feeding corn silage at 45% was more economical compared to feeding 15% corn silage, especially at higher corn prices, provided shrink is well managed. Feeding elevated concentrations of corn silage may be an economically viable method to control liver abscesses without antibiotic use.

Data were compiled from an experiment evaluating the effects of month of calving, wintering system, and calf management on cow and calf performance to model the amount of water (green and blue) required to produce beef in Nebraska production systems. The referenced study was conducted over four years utilizing 217 cow/calf pairs per year. Cows were wintered on either native range or corn residue and month of calving was March, June, or August. Calves were managed as calf-feds or yearlings and only steer calves were included in the model. A 365-d period was utilized to estimate the cow’s contribution of water inputs based on dry matter intake throughout the year varying by production system. Diet characteristics, dry-matter intake, days on feed, average daily gain, and hot carcass weight were measurements used to estimate water utilization by the calves. The total water footprint was calculated by dividing the total amount of water used for each system (L) by the amount of boneless beef produced (kg). Production systems where cows were wintered on corn residue utilized 18% less water than systems utilizing native range as a wintering source, because of water allocations using the value fraction method. Increasing the dietary inclusion of distillers grains from 0% to 40% decreased the water footprint in the finishing phase by 29%. Utilizing by-products in replacement of primary crops decreases the overall water footprint of production. Across all scenarios modeled, more than 50% of the water footprint was allocated to the cow grazing rainfed pasture (green water) and over 98% of the water footprint was allocated to growing feed. Improvements in crop water use efficiency will benefit livestock production. The water footprint of the beef systems analyzed was 80% green water as rain, minimizing the environmental impact of beef production on freshwater use and ecological water balance.

A 112 d finishing study was conducted to evaluate the effects of feeding dried distillers grains plus solubles (DDGS) from the MSC-Fiber stream of the FluidQuip post-fermentation fiber separation process compared to conventional DDGS. Yearling crossbred steers (n = 240, initial BW = 463 ± 35kg) were blocked by initial BW, stratified by BW, and assigned randomly to pen (n = 30; 8 steers/pen). Treatments were arranged as a 2×2 + 1 factorial with DDGS type (MSC DDGS [MSC]; Conventional DDGS [CONV]) and inclusion level (20 or 40% diet DM) as the factors. All treatments were compared to a corn-based control (CON). DDGS replaced a 60:40 blend of high-moisture corn and dry-rolled corn. All diets contained 7.5% alfalfa hay and supplement. Data were analyzed as a randomized block design with pen as experimental unit and block as fixed effect. Increasing concentrations of CONV or MSC resulted in a linear increase in DMI (P < 0.01). Steers fed 40% MSC had the greatest DMI (P < 0.01) while CON steers had the least (P < 0.02). Daily gains for MSC steers linearly increased (P = 0.03), while CONV steers showed a tendency for a quadratic response to ADG (P=0.08). Feed efficiency of CONV steers increased quadratically (P = 0.04) and tended to decrease linearly (P = 0.09) for steers fed MSC. Efficiency was greatest for 20% CONV but not different (P > 0.16) than CON, or 20% MSC. Steers fed 40% MSC or 40% CONV were not different in feed efficiency. Inclusion of MSC DDGS resulted in linear increases in DMI and ADG over CON, but decreased feed efficiency by 1.0 and 5.3% resulting in MSC DDGS having a relative feeding value of 95.0 and 86.7% of corn at 20 and 40% DM, respectively.

Growing crossbred steers [n = 80, initial body weight (BW) = 274 kg, SD = 21] were used to evaluate the effect of ad libitum and limit-fed intakes on methane (CH4) production. Two treatments with four pens per treatment (10 steers per pen) were evaluated in a randomized block designed experiment, with BW as a blocking factor. Treatments included feeding the same diet at ad libitum intake or limit fed at 75% of ad libitum intakes. Diet consisted of 45% alfalfa, 30% sorghum silage, 22% modified distillers grains plus solubles, and supplement at 3% on a dry matter (DM) basis. This trial was followed by a finishing trial (n = 80; initial BW = 369 kg; SD = 25) to evaluate the effects of dietary corn oil on CH4 production. Two treatments with four pens per treatment (10 steers per pen) were used in a randomized complete block designed experiment. Cattle were rerandomized and blocked by BW within the previous treatment. Treatments consisted of a control diet (CON) containing 66% corn, 15% wet distillers grains plus solubles, 15% corn silage, and 4% supplement (DM basis). Corn oil treatment (OIL) displaced 3% corn by adding corn oil. Methane was collected in two pen-scale chambers by collecting air samples continuously from pens by rotating every 6 min with an ambient sample taken between pen measurements. Steers fed ad libitum had greater DM intake (DMI) by design and greater average daily gain (ADG; P < 0.01) compared to limit-fed cattle; however, feed efficiency was not different between treatments (P = 0.40). Cattle fed ad libitum produced 156 g/d of CH4, which was greater (P < 0.01) than limit-fed cattle (126 g per steer daily). In the finishing trial, BW, gains, and carcass traits were not impacted by treatment (P ≥ 0.14). Feed efficiency (P = 0.02) improved because intakes decreased (P = 0.02) by feeding OIL compared to CON. Daily CH4 production was less (P = 0.03) for OIL-fed cattle (115 g per steer daily) compared to CON-fed cattle (132 g per steer daily). Methane was reduced (P < 0.01) by 17% for OIL-fed cattle compared to CON-fed cattle when expressed as grams of CH4 per kilogram of ADG. Feeding corn oil at 3% of diet DM reduced enteric CH4 production (grams per day) by 15%, which was only partially explained by a 3% decrease in DMI. Overall, a decrease in CH4 was observed when intake is limited in growing cattle and when corn oil is added in finishing diets.

Randomized complete block design experiments (n = 6 experiments) evaluating steroidal implants (all from Merck Animal Health, Madison, NJ) were conducted in large-pen feedlot research facilities between 2015 and 2018 comparing an 80 mg trenbolone acetate (TBA) and 8 mg estradiol-17β (E2) initial implant (Revalor-IH) and reimplanted with 200 mg TBA and 20 mg E2 (Revalor-200; REPEATED) to a single 80 mg TBA and 8 mg E2 uncoated; 120 mg TBA and 12 mg E2 coated implant (Revalor-XH) at arrival (SINGLE) on growth and carcass responses in finishing heifers. Experiments occurred in Nebraska, Oklahoma, Washington, and Texas. Similar arrival processing was used across experiments where 17,675 heifers [initial body weight = 333 kg SEM (4.1)] were enrolled into 180 pens (90 pens per treatment with 65–240 heifers per pen) and fed for 145–222 d. Only REPEATED heifers were removed from their pen at reimplant. Diets contained monensin and tylosin, consisted of ingredients common to each region, and contained greater than 90% concentrate. Ractopamine hydrochloride was fed for a minimum of 28 d prior to harvest. Linear mixed models were used for all analyses; model-adjusted means for each implant group and the corresponding SEM were generated. Distributions of U.S. Department of Agriculture (USDA) quality grade (QG) and yield grade (YG) were analyzed as ordinal outcomes. No differences (P ≥ 0.11) were detected for any performance parameters except dry matter intake (DMI), where SINGLE had greater (P = 0.02) DMI (9.48 vs. 9.38 ± 0.127 kg) compared with REPEATED. Heifers implanted with REPEATED had greater (P ≤ 0.02) hot carcass weight (HCW; 384 vs. 382 ± 2.8 kg), dressing percentage (64.54 vs. 64.22 ± 0.120%), and ribeye area (91.87 vs. 89.55 ± 0.839 cm2) but less (P ≤ 0.01) rib fat (1.78 vs. 1.83 ± 0.025 cm) and calculated YG (2.82 vs. 2.97 ± 0.040) and similar (P = 0.74) marbling scores (503 vs. 505 ± 5.2) compared with SINGLE heifers. Distributions of USDA YG and QG were impacted (P ≤ 0.03) by treatment such that REPEATED had fewer USDA Prime and YG 4 and 5 carcasses. Heifer growth performance did not differ between implant regimens, but HCW and muscling did, perhaps indicating that REPEATED may be suited for grid-based marketing, and SINGLE might be suited for heifers sold on a live basis depending upon market conditions and value-based grid premiums and discounts. However, these decisions are operational dependent and also may be influenced by factors including animal and employee safety, stress on animals, processing facilities, time of year, labor availability, and marketing strategies.

Two experiments were conducted to determine the effects of diet composition and time of urine spot sampling on estimates of urinary purine derivative (PD) excretion. In Exp. 1, 116 individually fed crossbred heifers (407 ± 32 kg) were arranged in a randomized block design (82 d). Treatments were arranged in a 2 × 3 factorial design, with two urine spot sample collection times (0700 and 1700 hours; AM and PM) and three diets: 85% steam-flaked corn (SFC); 85% SFC + 1.5% urea (UREA); or 25% SFC, 30% wet corn gluten feed, and 30% corn bran (BYPROD). In Exp. 2, six ruminally and duodenally fistulated steers (474 ± 37 kg) were arranged in a replicated 3 × 3 Latin square design, with dietary treatments identical to Exp. 1 (63 d). Treatment diets were selected to result in varied amounts of microbial crude protein (MCP) in order to evaluate the accuracy of using estimates of urinary PD excretion to predict MCP. Urine spot samples were collected at 0700, 1200, 1700, and 2200 hours. No urine collection time × diet interactions occurred (P > 0.20) for any variable in either experiment. In Exp. 1, dry matter intake (DMI) was greatest with BYRPOD (10.40 kg/d) and lowest with SFC (7.90 kg/d; P < 0.05). Feed efficiencies were greatest for UREA (0.182) and least for SFC (0.141; P < 0.05). Urinary PD:creatinine (PD:C) ratio was greatest for BYPROD (1.25) and least for SFC (0.94; P < 0.05). Urine spot sampling time had a significant (P < 0.05) impact on PD:C, 1.03 for AM and 1.22 for PM samples. In Exp. 2, DMI was greater (P < 0.05) with BYPROD than with SFC and tended (P = 0.07) to be greater with BYPROD than with UREA. Ruminal pH was greatest for BYPROD (5.94; P < 0.05). Flow of MCP was 636, 829, and 1,056 g/d for SFC, UREA, and BYPROD, with BYPROD being greater (P < 0.05) than SFC and tending (P = 0.06) to be greater than UREA. Urinary PD:C was greater (P < 0.05) for BYPROD than SFC and tended (P = 0.09) to be greater for UREA than SFC. Urinary PD:C increased linearly (P < 0.05) with sampling time. Diets formulated to affect DMI and MCP flow resulted in differences in urinary PD excretion, and these results related well with MCP flow estimated from duodenal purines. Collecting spot samples of urine later in the day resulted in greater estimates of urinary PD excretion; purine and PD flows appear to increase with time after one morning feeding per day. This method is well suited to evaluating relative differences between treatments but should not be extrapolated to assume absolute values.

A feedlot study was conducted comparing a natural feed additive at varying corn silage (CS) inclusions on receiving and finishing cattle performance. The study utilized 480 crossbred steers (initial shrunk body weight [BW] = 296 kg; SD = 24.1 kg) in 48 pens with 10 steers/pen and 8 pens per treatment. Treatments were designed as a 2 × 3 factorial with 3 inclusions of CS (14%, 47%, 80%; dry matter [DM] basis) with or without (+, −) the inclusion of a feed additive containing fumaric acid and palm oil (FAPO). All treatment diets contained 16% modified distillers grains plus solubles and 4% supplement with dry-rolled corn replacing CS on a DM basis. All steers were fed the 80 CS diet and adapted to 47% and 14% CS over a 10- and 24-d period, respectively. Cattle fed 80 CS were fed for 238 days, 47 CS for 195 days, and 14% CS were fed for 168 days to a common backfat of 1.28 cm (P ≥ 0.59). There were no interactions for CS inclusion and the inclusion of FAPO on final body weight (FBW), DMI, ADG, G:F, hot carcass weight (HCW), LM area, marbling, or calculated yield grade (CYG; P ≥ 0.15). There was no significant difference for FBW, DMI, ADG, G:F, HCW, marbling, or CYG for cattle fed with or without FAPO (P ≥ 0.13). However, there was a quadratic response for FBW, ADG, G:F, HCW, marbling, and CYG with increased inclusion of CS (P ≤ 0.04). Inclusion of FAPO had no effect on performance. Feeding CS at greater inclusions decreased daily gain and feed efficiency but increased FBW when fed to an equal fat endpoint. CS gave greater returns ($/animal) when fed at 80% of diet DM. Feeding greater amounts of CS can be an economical way to finish cattle. In this study, FAPO did not affect animal performance, carcass characteristics, or economic return.

In light of recent host-microbial association studies, a consensus is evolving that species composition of the gastrointestinal microbiota is a polygenic trait governed by interactions between host genetic factors and the environment. Here, we investigated the effect of host genetic factors in shaping the bacterial species composition in the rumen by performing a genome-wide association study. Using a common set of 61,974 single-nucleotide polymorphisms found in cattle genomes (n = 586) and corresponding rumen bacterial community composition, we identified operational taxonomic units (OTUs), Families and Phyla with high heritability. The top associations (1-Mb windows) were located on 7 chromosomes. These regions were associated with the rumen microbiota in multiple ways; some (chromosome 19; position 3.0–4.0 Mb) are associated with closely related taxa (Prevotellaceae, Paraprevotellaceae, and RF16), some (chromosome 27; position 3.0–4.0 Mb) are associated with distantly related taxa (Prevotellaceae, Fibrobacteraceae, RF16, RFP12, S24-7, Lentisphaerae, and Tenericutes) and others (chromosome 23; position 0.0–1.0) associated with both related and unrelated taxa. The annotated genes associated with identified genomic regions suggest the associations observed are directed toward selective absorption of volatile fatty acids from the rumen to increase energy availability to the host. This study demonstrates that host genetics affects rumen bacterial community composition.

Objectives were to evaluate the effects of de-oiled wet distillers bran plus solubles (WDBS) as a protein source [when included at 150 g/kg of diet dry matter (DM)] to replace soybean meal (SBM); or as a protein and energy source (when included at 300 and 450 g/kg of diet DM) to replace a mix of soybean meal, ground flint corn, and citrus pulp, and to evaluate the effects of corn oil inclusion (0 vs 30 g/kg of diet DM) in diets containing 0 to 450 g/kg of WDBS (DM basis). Two hundred and thirty-two Nellore bulls (BW = 425 ± 25 kg) were used in a randomized complete block design with a 2 × 4 factorial arrangement of treatments consisting of diets supplemented or not with 30 g/kg of corn oil (DM basis) each one combined with 4 inclusions of WDBS (0, 150, 300, and 450 g/kg; DM basis). Bulls were blocked by initial shrunk BW and allocated into 40 pens (5 pens/treatment; 5 or 6 bulls/pen). Effects of corn oil × WDBS interaction were not detected (P ≥ 0.29) for feedlot growth performance, carcass traits, and dietary NE concentrations, except for dry matter intake (DMI; P = 0.03). Increasing inclusion of WDBS linearly decreased DMI (P = 0.004) of finishing bulls fed diets without corn oil supplementation, but quadratically decreased DMI (P = 0.002) in diets containing 30 g/kg of corn oil, resulting in the observed interaction (P = 0.03). Feeding WDBS did not affect average daily gain (ADG), hot carcass weight (HCW), and dressing percentage of finishing bulls regardless of corn oil supplementation (P ≥ 0.18). Feed efficiency (G:F) tended (linear; P = 0.09) to increase due to WDBS inclusion. The inclusion of 30 g/kg corn oil (DM basis) in the diet tended (P = 0.07) to decrease DMI by 3% and increase G:F by 7.5% compared with diets not supplemented with corn oil. Including 30 g/kg of corn oil (DM basis) in the diet increased (P = 0.05) observed net energy of maintenance (NEm) and net energy of gain (NEg). Corn oil supplementation had no effect (P ≥ 0.19) on final BW, ADG, HCW, and dressing percentage. In summary, WDBS is as a protein supplement alternative to SBM when fed at 150 g/kg of the diet DM. The supplementation with corn oil is an effective way to increase the energy density of finishing diets containing WDBS.