Feedlot Operations Research Articles

Spatiotemporal patterns and source attribution of nitrogen load in a river basin with complex pollution sources

Environmental problems such as eutrophication caused by excessive nutrient discharge are global challenges. There are complex pollution sources of nitrogen (N) discharge in many river basins worldwide. Knowledge of its pollution sources and their respective load contributions is essential to developing effective N pollution control strategies. N loads from all known anthropogenic pollution sources in the Upper Huai River basin of China were simulated with the process-based SWAT (Soil and Water Assessment Tool) model. The performances of SWAT driven by daily and hourly rainfall inputs were assessed and it was found that the one driven by hourly rainfall outperformed the one driven by daily rainfall in simulating both total nitrogen (TN) and ammonia nitrogen (NH4-N) loads. The hourly SWAT model was hence used to examine the spatiotemporal patterns of TN and NH4-N loads and their source attributions. TN load exhibited significant seasonal variations with the largest in summer and the smallest in spring. Despite its declining proportion of contribution downstream, crop production remained the largest contributor of TN load followed by septic tanks, concentrated animal feedlot operations (CAFOs), municipal sewage treatment plants, industries, and scattered animal feedlot operations (SAFOs). There was much less seasonal variation in NH4-N load. CAFOs remained the largest source of NH4-N load throughout the basin, while contributions from industries and municipal sewage treatment plants were more evident downstream. Our study results suggest the need to shift the focus of N load reduction from “end-of-pipe” sewage treatment to an integrated approach emphasizing stakeholder involvement and source prevention.

English

A study on incidence of lumpy skin disease (LSD) was conducted at 20 exports-oriented cattle feedlots found in Adama district in Central Ethiopia between June and December, 2011. The 11,189 bulls in the 20 exports-oriented feedlots were clinically examined and evaluated for LSD, its incidence, mortality and morbidity. The overall incidence and mortality rate of LSD in cattle feedlots was 6.1 and 1.8% respectively. Statistically significant difference was observed among sites of feedlots operations in incidence (χ2 = 251.4, df = 5, p < 0.05) and mortality rate (χ2 = 167.9, df = 5, p < 0.05). The overall case fatality of the disease was 30% with significant difference among all feedlot operation sites (χ2 = 326.7, df = 5, p < 0.05). Majority of the affected population was observed with variable degree of lameness that was accompanied with edema of limbs with the progression of the disease. The nodules became necrotic, and eventually a deep scab formed (sit-fast).  The results of this study indicated that the complex epidemiological situation of the disease in Ethiopia needs more detailed investigation if improved vaccine-based control is to be achieved effectively and efficiently.   Key words: Cattle, Central Ethiopia, feedlots, lumpy skin disease.&nbsp

Feeding behavior as an early predictor of bovine respiratory disease in North American feedlot systems.

Bovine respiratory disease (BRD), which can cause substantial losses for feedlot operations, is often difficult to detect based solely on visual observations. The objectives of the current study were to determine a BRD case identification based on clinical and laboratory parameters and assess the value of feeding behavior for early detection of BRD. Auction-derived, mixed-breed beef steers (n = 213) with an average arrival weight of 294 kg were placed at a southern Alberta commercial feedlot equipped with an automated feed bunk monitoring system. Feeding behavior was recorded continuously (1-s intervals) for 5 wk after arrival and summarized into meals. Meals were defined as feeding events that were interrupted by less than 300 s nonfeeding. Meal intake (g) and meal time (min) were further summarized into daily mean, minimum, maximum, and sum and, together with frequency of meals per day, were fit into a discrete survival time analysis with a conditional log-log link. Feedlot staff visually evaluated (pen-checked) health status twice daily. Within 35 d after arrival, 76% (n = 165) of the steers had 1 or more clinical signs of BRD (reluctance to move, crusted nose, nasal or ocular discharge, drooped ears or head, and gaunt appearance). Whereas 41 blood samples could not be processed due to immediate freezing, for 124 of these steers, complete and differential blood cell count, total serum protein, plasma fibrinogen, serum concentration of haptoglobin (HP), and serum amyloid A (SAA) were determined. The disease definition for BRD was a rectal temperature ≥ 40.0°C, at least 2 clinical signs of BRD, and HP > 0.15 mg/mL. It was noteworthy that 94% of the 124 steers identified by the feedlot staff with clinical signs of BRD had HP > 0.15 mg/mL. An increase in mean meal intake, frequency, and mean inter-meal interval was associated with a decreased hazard for developing BRD 7 d before visual identification (P < 0.001). Furthermore, increased mean mealtime, frequency, and mean inter-meal interval were associated with a decreased BRD hazard up to 7 d before feedlot staff noticed clinical symptoms (P < 0.001). In conclusion, mean intake per meal as well as mean meal time and frequency of meals could be used to predict the hazard of BRD in feedlot cattle 7 d before visual detection and could be considered in commercial feedlot settings once a predictive algorithm has been developed.

Spatiotemporal distribution of soil nutrients within an abandoned cattle feedlot

Purpose Nutrients from cropland and feedlot operations can move through preferential pathways into wetlands, groundwater, and surface water, which can cause adverse health and ecological problems. It is hypothesized that nitrogen (N) can cause a short-term contamination of soils and groundwater beneath feedlots, but phosphorus (P) can cause both short- and long-term contamination in well-drained soils. This paper examines the spatial and temporal distribution of nutrients within an abandoned feedlot and adjacent wetlands.

Determining the effectiveness of optimal time-varying hedge ratios for cattle feeders under multiproduct and single commodity settings

Purpose – The purpose of this paper is to determine and contrast the risk mitigating effectiveness from optimal multiproduct time-varying hedge ratios, applied to the margin of a cattle feedlot operation, over single commodity time-varying and naive hedge ratios. Design/methodology/approach – A parsimonious regime-switching dynamic correlations (RSDC) model is estimated in two-stages, where the dynamic correlations among prices of numerous commodities vary proportionally between two different regimes/levels. This property simplifies estimation methods for a large number of parameters involved. Findings – There is significant evidence that resulting simultaneous correlations among the prices (spot and futures) for each commodity attain different levels along the time-series. Second, for in and out-of-sample data there is a substantial reduction in the operation's margin variance provided from both multiproduct and single time-varying optimal hedge ratios over naive hedge ratios. Lastly, risk mitigation is attained at a lower cost given that average optimal multiproduct and single time-varying hedge ratios obtained for corn, feeder cattle and live cattle are significantly below the naive full hedge ratio. Research limitations/implications – The application studied is limited in that once a hedge position has been set at a particular period, it is not possible to modify or update at a subsequent period. Practical implications – Agricultural producers, specifically cattle feeders, may profit from a tool using improved techniques to determine hedge ratios by considering a larger amount of up-to-date information. Moreover, these agents may apply hedge ratios significantly lower than one and thus mitigate risk at lower costs. Originality/value – Feedlot operators will benefit from the potential implementation of this parsimonious RSDC model for their hedging operations, as it provides average optimal hedge ratios significantly lower than one and sizeable advantages in margin risk mitigation.

Bovine diseases causing neurological signs and death in Mexican feedlots

The number of large feedlot operations, similar to that of USA and Canada, has notably increased in Mexico in the last three decades. Clinical and laboratory diagnoses of neurological diseases in feedlot cattle are crucial in Mexico and Central America because of the high incidence of bovine paralytic rabies (BPR). Because of its zoonotic potential, BPR must be promptly diagnosed and differentiated from other bovine neurological diseases such as thrombotic meningoencephalitis (TME), polioencephalomalacia (PEM) and botulism. More recently, BPR and botulism have been diagnosed with increasing frequency in Mexican feedlots. Neither BPR nor botulism has relevant gross lesions, thus post-mortem diagnosis without laboratory support is impossible. Herein, we describe five outbreaks of neurological diseases in Mexican feedlots in which BPR, botulism and PEM were diagnosed either independently or in combination. A diagram illustrating the most conspicuous pathologic findings and ancillary laboratory test required to confirm the diagnoses of these neurological diseases in feedlot cattle is proposed.

Simulation modelling of a hypothetical introduction of foot-and-mouth disease into Alberta

This study describes the use of simulation modelling to evaluate the predicted benefits of an effective livestock traceability system in responding to a hypothetical introduction of foot-and-mouth disease (FMD) in to the province of Alberta, Canada, and whether or not the implementation of emergency ring vaccination in addition to a standard stamping-out (SO) strategy would lead to smaller and shorter epidemics. Three introduction scenarios were defined, with the primary case in either an intensive beef feedlot operation, an extensive cow–calf operation or in a swine operation. Disease spread was simulated using, three levels of tracing effectiveness, five types of vaccination zone, three different vaccination start times, three lengths of vaccination campaigns, two levels of culling resource and using FMD strains with two different virulence levels. Using standard SO procedures (without vaccination), improving traceability effectiveness from a level whereby only 65% of movements were traced within 5–7 days, to a capability whereby all movements were traced within 1 day, led to a reduction in the number of infected premises (IPs) between 18.7 and 64.5%, an average saving of CAN$29,000,000 in livestock compensation costs alone, and a reduction in the length of epidemics ranging from 1 to 22 days. The implementation of emergency vaccination also led to a reduction in the number of IPs and a shortening of epidemics. The effects were more pronounced when the higher virulence settings were used, with a predicted reduction in IPs of 16.6–68.7% (mean=48.6%) and epidemics shortened by up to 37 days. Multi-variable analyses showed these effects were highly significant, after accounting for the incursion location, virulence of virus and time of first detection. The results clearly demonstrated the benefits of having effective traceability systems with rapid query and reporting functionality. The results also supported the value of early vaccination as an adjunct to SO in reducing the number of IPs and shortening the length of the epidemics. The most effective vaccination strategy involved a 3km or larger suppressive vaccination zone around all IPs, begun as soon as practicable after first detection, and which continued until the last IP was detected.

A simulation-based approach for evaluating and comparing the environmental footprints of beef production systems1

A methodology was developed and used to determine environmental footprints of beef cattle produced at the U.S. Meat Animal Research Center (MARC) in Clay Center, NE, with the goal of quantifying improvements achieved over the past 40 yr. Information for MARC operations was gathered and used to establish parameters representing their production system with the Integrated Farm System Model. The MARC farm, cow-calf, and feedlot operations were each simulated over recent historical weather to evaluate performance, environmental impact, and economics. The current farm operation included 841 ha of alfalfa and 1,160 ha of corn to produce feed predominately for the beef herd of 5,500 cows, 1,180 replacement cattle, and 3,724 cattle finished per year. Spring and fall cow-calf herds were fed on 9,713 ha of pastureland supplemented through the winter with hay and silage produced by the farm operation. Feedlot cattle were backgrounded for 3 mo on hay and silage with some grain and finished over 7 mo on a diet high in corn and wet distillers grain. For weather year 2011, simulated feed production and use, energy use, and production costs were within 1% of actual records. A 25-yr simulation of their current production system gave an average annual carbon footprint of 10.9±0.6 kg of CO2 equivalent units per kg BW sold, and the energy required to produce that beef (energy footprint) was 26.5±4.5 MJ/kg BW. The annual water required (water footprint) was 21,300±5,600 L/kg BW sold, and the water footprint excluding precipitation was 2,790±910 L/kg BW. The simulated annual cost of producing their beef was US$2.11±0.05/kg BW. Simulation of the production practices of 2005 indicated that the inclusion of distillers grain in animal diets has had a relatively small effect on environmental footprints except that reactive nitrogen loss has increased 10%. Compared to 1970, the carbon footprint of the beef produced has decreased 6% with no change in the energy footprint, a 3% reduction in the reactive nitrogen footprint, and a 6% reduction in the real cost of production. The water footprint, excluding precipitation, has increased 42% due to greater use of irrigated corn production. This proven methodology provides a means for developing the production data needed to support regional and national full life cycle assessments of the sustainability of beef.

Impact of livestock production type vaccination priority order on the control of a foot and mouth disease outbreak in the central United States

The central United States (US) has a large livestock population including cattle, swine, sheep, and goats that are fully susceptible to foot and mouth disease (FMD). Introduction of FMD to the US would have potentially devastating consequences to the livestock industry. Identification of optimal control measures including potential vaccination strategies is essential to minimize the impact of a FMD outbreak. Both dairy and large feedlot operations have frequent indirect contacts, which make them key production types for FMD transmission and thus should be the focus of control strategies. To address this issue, we developed simulation scenarios to assess the impact of livestock production type vaccination priority on FMD outbreaks using the North American Animal Disease Spread Model (NAADSM), a spatially explicit, stochastic infectious disease model.

Long‐Term Manure Applications Impact on Irrigated Barley Forage Mineral Concentrations

Long‐term manure use near livestock feedlot operations can result in soil nutrient imbalances. We investigated the impact of continuous (37‐yr) and discontinued (30‐yr continuous + 7 yr without applications) manure applications on soil properties and barley (Hordeum vulgare L.) yield and nutritive value under semiarid field conditions in southern Alberta, Canada. Feedlot cattle manure annual applications were 0, 60, 120, and 180 Mg ha–1 (wet weight) to an irrigated Chernozemic soil. After 37 yr, barley yields were not affected by manure applications, while forage crude protein (CP), NO3–N, P, K, and Zn concentrations increased (P &lt; 0.01). Forage Ca/P ratios decreased and K/(Ca + Mg) ratios increased with manure applications to critical levels of illness potential in ruminants. Discontinuing manure applications did not affect forage CP content; however, forage P and K concentrations declined (P &lt; 0.01) with decreases in soil P and K. This resulted in the return of forage Ca/P ratios within the recommended levels. Seven years after manure applications were discontinued, forage Zn concentrations were similar to concentrations from unmanured plots. Although forage nutrient balances for animal nutrition improved after manure applications were discontinued, soil nutrient recovery was small, and soil P, K, and Zn concentrations in the discontinued plots remained greater (P &lt; 0.01) than concentrations in the unmanured plots and well above those required for optimum crop growth.

INSTALLATION OF 42 KW SOLAR PHOTOVOLTAICS AND 50 KW WIND TURBINE SYSTEMS

INTRODUCTION A solar photovoltaic (PV) system and a wind turbine system are to be utilized to reduce energy use from the electrical grid consumption at West Texas A&M University (WTAMU) through the use of renewable energy. WTAMU's Alternative Energy Institute (AEI) performed the installation of the PV/wind turbine systems. A 42 kW PV system located at the Palo Duro Research Facility (PDRF) is suitable to offset the energy use of the PDRF since the energy consumed by the facility is primarily during the daytime, with a peak energy use of approximately 225 kW. The expected energy match of 42 kW compared to the typical daily energy consumption of the building (75–80 kW) will have a significant impact on grid energy cost for this office and research space. A 50 kW wind turbine system located at WTAMU's Nance Ranch produces the energy required by its cattle feedlot operations. It consumed approximately 125,000 kWh of electricity based on data monitored from June 2011 to May 2012. The majority of the energy use...

Impact of system management on vegetative treatment system effluent concentrations

Beef feedlots of all sizes are looking for more cost-effective solutions for managing feedlot runoff. Vegetative treatment systems are one potential option, but require performance evaluation for use on concentrated animal feeding operations. The performance of six vegetative treatment systems on open beef feedlots throughout Iowa was monitored from 2006 through 2009. These feedlots had interim, National Pollution Discharge Elimination System permits that allowed the use of vegetative treatment systems to control and treat runoff from the open feedlots. This manuscript focuses on making within site comparisons, i.e., from year-to-year and component-to-component within a site, to evaluate how management changes and system modifications altered performance. The effectiveness, in terms of effluent concentration reductions, of each system was evaluated; nutrient concentration reductions typically ranged from 60 to 99% during treatment in the vegetative components of the vegetative treatment systems. Monitoring results showed a consistent improvement in system performance during the four years of study. Much of this improvement can be attributed to improved management techniques and system modifications that addressed key performance issues. Specifically, active control of the solid settling basin outlet improved solids retention and allowed the producers to match effluent application rates to the infiltration rate of the vegetative treatment area, reducing the occurrence of effluent release. Additional improvements resulted from system maturation, increased operator experience, and the addition of earthen flow spreaders within the vegetative treatment area to slow flow and provide increased effluent storage within the treatment area, and switching to active management of settling basin effluent release.

Occurrence of ectoparasiticides in Australian beef cattle feedlot wastes

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous analysis of 6 ectoparasiticides – 2 synthetic pyrethroids (deltamethrin, cypermethrin) and 4 macrocyclic lactones (abamectin, doramectin, ivermectin and eprinomectin) in biosolids. The method was used to investigate the occurrence of these ectoparasiticides in beef cattle feedlot wastes in Australia from 5 commercial feedlot operations which employ varying waste management practices. Deltamethrin and cypermethrin were not detected in any of the samples while abamectin, ivermectin, doramectin and eprinomectin were detected in some of the samples with concentrations ranging from 1 to 36 μg/kg dry weight (d.w.) freeze dried feedlot waste. Levels of macrocyclic lactones detected in the feedlot wastes varied and were dependent on sample type. The effect of seasonal variations and waste management practices were also investigated in this study.

Risk assessments of lumpy skin diseases in Borena bull market chain and its implication for livelihoods and international trade.

Risks of introduction of lumpy skin disease (LSD) through traded Borena bulls to market chain and its consequences were assessed. The assessment used the framework that has been recommended by the World Animal Health Organization (OIE) for risk analysis. Likelihoods for release and exposure were estimated by a qualitative scale ranging from negligible to very high, whereas the consequences which resulted from disease occurrences were assessed quantitatively. The likelihood of the introduction of LSD to the market chain through traded Borena bulls is found to be high (medium uncertainty), whereas the probability of exposure is very high (medium uncertainty). From the total of 11,189 bulls observed during outbreak investigation of LSD in six sites of feedlot operation in and around Adama, 681(6.1 %) and 204 (1.8 %) bulls were found to be affected and dead with LSD, respectively. The total economic loss due to LSD was estimated to be 667,785.6 USD. The risk estimates for LSD are greater than negligible; therefore, disease prevention and control strategy along the chain should be carefully considered by the Ethiopian veterinary services.

Integrating stochasticity into the objective function avoids Monte Carlo computation in the optimisation of beef feedlots

The real world contains many sources of natural variation. Useful simulation models of real-world problems, such as the optimal allocation of beef cattle into feedlot pens, need to take this into account. Monte Carlo simulation is the usual method of achieving this, using multiple model runs, each with a different set of randomly generated variables. However, when the goal is system optimisation, this approach can make the computation extremely intensive, and difficult for the optimisation of even moderately-sized models. This problem was addressed in an industry model of feedlot operations, where animals are selected and drafted into separate pens, and grown to the optimal weight and fat ranges in the pricing grid. For each pen, it is planned that the majority of the animals achieve this targeted region of the price grid, so that the number of discounted carcasses will be minimal. The main problem is that animals which appear reasonably similar at intake then display variable growth and fattening rates. Hence deterministic predictions are unrealistic, and stochasticity needs to be factored in. However this interferes with the efficient optimisation of this feedlot operation, which ultimately needs to be done ‘real-time’ (at animal induction), and on-site at the feedlot. Our solution to this dilemma was to transfer all of the modelled stochastic processes onto the evaluation side of this problem, by integrating over Normal distributions applied to the expected prices for each animal. This allows the optimisation runs to directly estimate the expected economic outcome using just one model evaluation for each trial management strategy. This process is illustrated with two case-studies, based on separate past intakes of animals into a commercial feedlot. For both intakes, the simulated results as reflected by the carcass values for the actual times on feed matched well with the observed values. Simulated results indicate that increases in profitability can be obtained both by altering the days on feed, and by better allocation of the animals to the pens. The overall predicted increase in profit per animal was $34 for the first intake, where the actual allocation of animals to the pens was approximately random (the order they were offloaded), and $20 for the second example where the animals had been allocated to pens on a more structured basis (by weights). This optimised allocation scheme appears to offer obvious improvements for feedlot operations, and is currently being trialed by a number of industry collaborators.

Utilizing single particle Raman microscopy as a non-destructive method to identify sources of PM10 from cattle feedlot operations

Emissions of particulate matter (PM) from animal feeding operations (AFOs) pose a potential threat to the health of humans and livestock. Current efforts to characterize PM emissions from AFOs generally examine variations in mass concentration and particle size distributions over time and space, but these methods do not provide information on the sources of the PM captured. Raman microscopy was employed as a non-destructive method to quantify the contributions of source materials to PM10 emitted from a large cattle feedlot. Raman spectra from potential source materials (dust from unpaved roads, manure from pen surface, and cattle feed) were compiled to create a spectral library. Multivariate statistical analysis methods were used to identify specific groups composing the source library spectra and to construct a linear discriminant function to identify the source of particles collected on PM10 sample filters. Cross validation of the model resulted in 99.76% correct classification of source spectra in the training group. Source characterization results from samples collected at the cattle feedlot over a two-day period indicate that manure from the cattle pen surface contributed an average of 78% of the total PM10 particles, and dust from unpaved roads accounted for an average of 19% with minor contributions from feed. Results of this work are promising and provide support for further investigation into an innovative method to identify agricultural PM10 sources accurately under different meteorological and management conditions.

Modelling defined mixtures of environmental oestrogens found in domestic animal and sewage treatment effluents using an in vitro oestrogen‐mediated transcriptional activation assay (T47D‐KBluc)

There is growing concern of exposure of fish, wildlife and humans to water sources contaminated with oestrogens and the potential impact on reproductive health. Environmental oestrogens can come from various sources including concentrated animal feedlot operations (CAFO), municipal waste, agricultural and industrial effluents. US EPA's drinking water contaminant candidate list 3 (CCL3) includes several oestrogenic compounds. Although these contaminants are currently not subject to any proposed or promulgated national primary drinking water regulations, they are known or anticipated to occur in public water systems and may require future regulation under the Safe Drinking Water Act. Using an in vitro transcriptional activation assay, this study evaluated oestrogens from CCL3 both individually and as a seven oestrogen mixture (fixed ray design) over a broad range of concentrations, including environmentally relevant concentrations. Log EC(50) and Hillslope values for individual oestrogens were as follows: estrone, -11.92, 1.283; estradiol-17α, -9.61, 1.486; estradiol-17β, 11.77, 1.494; estriol, -11.14, 1.074; ethinyl estradiol-17α, -12.63, 1.562; Mestranol, -11.08, 0.809 and Equilin, -11.48, 0.946. In addition, mixtures that mirrored the primary oestrogens found in swine, poultry and dairy CAFO effluent (fixed-ratio ray design), and a ternary mixture (4 × 4 × 4 factorial design) of oestrogens found in hormone replacement therapy and/or oral contraceptives were tested. Mixtures were evaluated for additivity using both the concentration addition (CA) model and oestrogen equivalence (EEQ) model. For each of the mixture studies, a broad range of concentrations were tested, both above and below environmentally relevant concentrations. Results show that the observed data did not vary consistently from either the CA or EEQ predictions for any mixture. Therefore, either the CA or EEQ model should be useful predictors for modelling oestrogen mixtures.

Plasmid-Mediated Quinolone Resistance Genes and Antibiotic Residues in Wastewater and Soil Adjacent to Swine Feedlots: Potential Transfer to Agricultural Lands

Background: Inappropriate use of antibiotics in swine feed could cause accelerated emergence of antibiotic resistance genes, and agricultural application of swine waste could spread antibiotic resistance genes to the surrounding environment.Objectives: We investigated the distribution of plasmid-mediated quinolone resistance (PMQR) genes from swine feedlots and their surrounding environment.Methods: We used a culture-independent method to identify PMQR genes and estimate their levels in wastewater from seven swine feedlot operations and corresponding wastewater-irrigated farm fields. Concentrations of (fluoro)quinolones in wastewater and soil samples were determined by ultra-performance liquid chromatography–electrospray tandem mass spectrometry.Results: The predominant PMQR genes in both the wastewater and soil samples were qnrD, qepA, and oqxB, whereas qnrS and oqxA were present only in wastewater samples. Absolute concentrations of all PMQR genes combined ranged from 1.66 × 107 to 4.06 × 108 copies/mL in wastewater and 4.06 × 106 to 9.52 × 107 copies/g in soil. Concentrations of (fluoro)quinolones ranged from 4.57 to 321 ng/mL in wastewater and below detection limit to 23.4 ng/g in soil. Significant correlations were found between the relative abundance of PMQR genes and (fluoro)quinolone concentrations (r = 0.71, p = 0.005) and the relative abundance of PMQR genes in paired wastewater and agricultural soil samples (r = 0.91, p = 0.005).Conclusions: Swine feedlot wastewater may be a source of PMQR genes that could facilitate the spread of antibiotic resistance. To our knowledge, this is the first study to examine the occurrence of PMQR genes in animal husbandry environments using a culture-independent method.

Wheat distillers grains in feedlot cattle diets: Feeding behavior, growth performance, carcass characteristics, and blood metabolites1,2

A study was conducted to evaluate feed intake, ADG, carcass quality, eating behavior, and blood metabolites in feedlot beef steers fed diets that varied in proportion of wheat dried distillers grains with solubles (DDGS) replacing barley grain or barley silage. Two hundred crossbred steers (BW = 489 ± 30 kg) were blocked by BW and randomly allotted to 20 pens (5 pens per treatment). Steers were fed 1 of 4 diets: control without DDGS (CON), 25% (25DDGS), 30% (30DDGS), or 35% (35DDGS) wheat DDGS (DM basis). The CON diet consisted of 15% barley silage and 85% barley-based concentrate; the 3 wheat DDGS diets were formulated by substituting 20% barley grain and 5, 10, or 15% silage, respectively, with 25, 30, or 35% wheat DDGS so that the 35DDGS diet contained no silage. The diets were formulated such that wheat DDGS was substituted for both barley grain and barley silage to evaluate whether wheat DDGS can be fed as a source of both energy and fiber in feedlot finishing diets. Dry matter intake of steers fed 25DDGS was greater (P < 0.01), but final BW, ADG, and G:F were not different compared with steers fed CON diet. Carcass characteristics and liver abscess score were not different between CON and 25DDGS. Steers fed 25DDGS had longer eating time (min/d; P < 0.01), greater meal frequency (P < 0.04), but a slower eating rate (P < 0.04). Replacing barley silage with increasing amounts of wheat DDGS (from 25DDGS to 35DDGS) linearly reduced (P < 0.01) DMI. Final BW, ADG, and G:F were not affected by increasing amounts of wheat DDGS. Carcass traits were not different, whereas liver abscess scores linearly (P < 0.01) increased as more barley silage was replaced by wheat DDGS. Eating time (min/d) and duration of each meal linearly (P < 0.02) decreased, whereas eating rate (min/g of DM) linearly (P < 0.01) increased with increasing replacement of barley silage. Blood urea N was doubled (P < 0.01) compared with CON by inclusion of wheat DDGS. Results indicate that wheat DDGS can be used effectively in feedlot diets, decreasing the need for barley grain or silage without negatively affecting growth performance and carcass characteristics. A reduction in the amount of roughage required to maintain growth performance is a potential advantage in feedlot operations because forage is costly and often of limited availability. Thus, DDGS can be a possible alternative as long as they are available and cost effective; however, increased incidence of liver abscess and increased N content of manure need to be considered when greater amounts of wheat DDGS are included in finishing diets.

Comparison of Construction Costs for Vegetative Treatment Systems in the Midwestern United States

Vegetative treatment systems (VTSs) provide an alternative to containment basin systems for beef feedlot runoff control. Beef producers in the Midwestern United States have shown an increasing interest in using VTSs as a perceived lower cost option to containment basin systems. This article reports the actual construction costs associated with 23 VTSs (nine on permitted Concentrated Animal Feeding Operations (CAFOs) and 14 on non-permitted Animal Feeding Operations (AFOs)) and four containment basins located throughout Iowa, Minnesota, South Dakota, and Nebraska. The VTS construction costs are reported on a per head space basis in 2009 adjusted dollars for each system. Cost comparisons are presented for CAFO and AFO facilities, and by system type. Additionally, estimated construction cost comparisons between open feedlots with VTS systems, open feedlots with containment basins, monoslope barns and hoop structures for beef production systems are provided. Results from the cost comparison indicate the average construction cost in 2009 dollars for an AFO or CAFO is $655 per head space for animals housed in a monoslope barn with a concrete floor and $395 per head space for animals housed in a hoop structure. For AFOs and CAFOs, the average cost of an earthen lot with a containment basin costs is $361 per head space, while the average cost of an earthen lot implemented with a VTS is $283 per head space. If only the feedlot runoff control system is considered, VTSs designed for CAFO facilities are less expensive on average to construct ($85 per head space on average) than traditional containment basins ($136 per head space on average). Similarly for AFO feedlot runoff control systems, a VTS was less expensive to build on average ($79 per head space on average.) than a containment basin on a similar facility ($205 per head space). The data indicated on average the least expensive VTS for an AFO is a gravity VTS ($54 per head space average.) followed by a sprinkler VTS ($94 per head space average.) and a pump and gravity VTS ($101 per head space average.). Statistical analysis showed no significant difference between the VTS construction cost per head space of cattle for an AFO compared to a CAFO (p=0.07, alpha=0.05) while there was a statistical difference between system type (p=0.02, alpha=0.05).