Pen Surface Research Articles

Greenhouse Gas Emissions from Ground Level Area Sources in Dairy and Cattle Feedyard Operations

A protocol that consisted of an isolation flux chamber and a portable gas chromatograph was used to directly quantify greenhouse gas (GHG) emissions at a dairy and a feedyard operation in the Texas Panhandle. Field sampling campaigns were performed 5 consecutive days only during daylight hours from 9:00 am to 7:00 pm each day. The objective of this research was to quantify and compare GHG emission rates (ERs) from ground level area sources (GLAS) at dairy and cattle feedyard operations during the summer. A total of 74 air samples using flux chamber were collected from the barn (manure lane and bedding area), loafing pen, open lot, settling basin, lagoons, and compost pile within the dairy operation. For the cattle feedyard, a total of 87 air samples were collected from four corner pens of a large feedlot, runoff holding pond, and compost pile. Three primary GHGs (methane, carbon dioxide, and nitrous oxide) were measured and quantified from both operations. The aggregate estimated ERs for CH4, CO2, and N2O were 836, 5573, 3.4 g hd−1 d−1 (collectively 27.5 kg carbon dioxide equivalent (CO2e) hd−1 d−1), respectively, at the dairy operation. The aggregate ERs for CH4, CO2, and N2O were 3.8, 1399, 0.68 g hd−1 d−1 (1.7 kg CO2e hd−1 d−1), respectively, from the feedyard. The estimated USEPA GHG ERs were about 13.2 and 1.16 kg CO2e hd−1 d−1, respectively, for dairy and feedyard operations. Aggregate CH4, CO2 and N2O ERs at the dairy facility were about 219, 4 and 5 times higher, respectively, than those at the feedyard. At the dairy, average CH4 ERs estimated from the settling basin, primary and secondary lagoons were significantly higher than those from the other GLAS, contributing about 98% of the aggregate CH4 emission. The runoff holding pond and pen surface of the feedyard contributed about 99% of the aggregate CH4 emission. Average CO2 and N2O ERs estimated from the pen surface area were significantly higher than those estimated from the compost pile and runoff pond. The pen surface alone contributed about 93% and 84% of the aggregate CO2 and N2O emission, respectively. Abatement and management practices that address GHG emissions from these sources will likely be most effective for reducing facility emissions.

Bacterial Community Analysis of Beef Cattle Feedlots Reveals That Pen Surface Is Distinct from Feces

The surface of beef cattle feedlot pens is commonly conceptualized as being packed uncomposted manure. Despite the important role that the feedlot pen may play in the transmission of veterinary and zoonotic pathogens, the bacterial ecology of feedlot surface material is not well understood. Our present study characterized the bacterial communities of the beef cattle feedlot pen surface material using 3647 full-length 16S rDNA sequences, and we compared the community composition of feedlot pens to the fecal source material. The feedlot surface composite was represented by members of the phylum Actinobacteria (42%), followed by Firmicutes (24%), Bacteroidetes (24%), and Proteobacteria (9%). The feedlot pen surface material bacterial communities were clearly distinct from those of the feces from animals in the same pen. Comparisons with previously published results of feces from the animals in the same pen reveal that, of 139 genera identified, only 25 were present in both habitats. These results indicate that, microbiologically, the feedlot pen surface material is separate and distinct from the fecal source material, suggesting that bacteria that originate in cattle feces face different selection pressures and survival challenges during their tenure in the feedlot pen, as compared to their residence in the gastrointestinal tract.

Environmental Conditions in Beef Deep-Bedded Mono-Slope Facilities: A Descriptive Study

In the Northern Great Plains, interest in feeding cattle in enclosed beef deep-bedded mono-slope facilities (BDMF) has increased. Characterization of environmental factors impacting odor and gas emissions, nutrient excretion, and pathogens is needed to develop recommendations for management of BDMF. The objectives of this study were to determine spatial variability of ammonia (NH3) in the air and odorous volatile organic compounds (VOC) in the bedded pack and to quantify environmental factors during various seasons. The effects of environmental factors on concentrations of NH3 and VOC were determined. The nutrient content and occurrence of E. coli O157:H7 and generic E. coli concentrations in bedded pack material were also determined. High spatial variability was observed for steady-state NH3 concentration on the pen surface. Ammonia concentration increased as pack and ambient air temperatures increased (p < 0.01). The temperature humidity index inside the barn was significantly greater than outside the barn during hot and cold months. Concentrations of VOC were highest in transition areas between the bedded pack and the concrete floor. Depth, moisture content, and pH of the bedded pack were poorly correlated to concentrations of NH3 and VOC (r2 < 0.09). Manure from BDMF contained 80% volatile solids. E. coli O157:H7 prevalence and generic E. coli concentrations occurred at high levels in BDMF and varied seasonally. Priority should be given to NH3 and E. coli mitigation during hot months, but location-specific NH3 mitigation will not be effective due to random distribution in the pen. Frequent cleaning of areas surrounding the bedded pack should reduce VOC concentrations.

Supporting Automated Pen and Ink Style Surface Illustration with B-Spline Models

This paper introduces a methodology for constructing pen and ink style landscape illustrations using B-spline surface models. Following a brief discussion of manual methods and recent developments in automated non-photorealistic rendering (NPR) techniques, the paper discusses polynomial models for surface rendering and their implementation in the OpenGL graphics interface. It then discusses the generation of silhouettes and form lines for topographic surfaces from a set of triangulated vertices obtained from polygonal tessellations. An implementation of the methodology outlined in the paper is described and tested. The results are analyzed and suggestions for further research are presented.

Measuring Cattle Feedlot Dust Using Laser Diffraction Analysis

Considerable amounts of particulate matter (PM), including total suspended particulates (TSP), particulates with equivalent aerodynamic diameter less than or equal to 10 m (PM10), and particulates with equivalent aerodynamic diameter less than or equal to 2.5 m (PM2.5), are emitted from large beef cattle feedlots. Particle size distribution and concentrations of TSP, PM10, and PM2.5 at a commercial cattle feedlot in Kansas were measured over a two-year period. The feedlot had a capacity of 30,000 head with a total pen area of 50 ha and was equipped with a sprinkler system for dust control. Collocated low-volume samplers for TSP, PM10, and PM2.5 were used to measure concentrations of TSP, PM10, and PM2.5 at the upwind and downwind edges of the feedlot. A laser diffraction (LD) analyzer (Beckman Coulter LS 13 320) was utilized to determine the particle size distribution of dust samples collected by TSP samplers. A micro-orifice uniform deposit impactor (MOUDI) was also used to measure particle size distribution at the downwind edge of the feedlot. Considering the same effective size range, the LD analyzer and MOUDI did not differ significantly in mean geometric mean diameter (GMD) (11.6 vs. 13.0 m) and in mean geometric standard deviation (2.3 vs. 2.3). Wind speed and period of sampling significantly affected the mean GMD of the particles. The PM10 and PM2.5 concentrations that were calculated from the LD method and TSP data were not significantly different from those measured by low-volume PM10 and PM2.5 samplers (122 vs. 131 g m-3 for PM10 and 26 vs. 35 g m-3 for PM2.5). Both PM10 and PM2.5 fractions decreased as pen surface water content increased, but the PM2.5/PM10 ratio showed little change as pen surface water content increased.

Soil versus Pond Ash Surfacing of Feedlot Pens: Occurrence of Escherichia coli O157:H7 in Cattle and Persistence in Manure.

Reducing Escherichia coli O157:H7 in cattle and their manure is critical for reducing the risk for human foodborne and waterborne illness. The objective of this study was to evaluate the effects of soil and pond ash surfaces for feedlot pens on the prevalence, levels, and/or persistence of naturally occurring E. coli O157:H7 and total E. coli in cattle (feces and hides) and manure. Cattle (128 beef heifers) were sorted among 16 pens: 8 surfaced with soil and 8 surfaced with pond ash. The prevalence of E. coli O157:H7 in feces decreased (P < 0.0001) during the study from 57.0% on day 0 to 3.9% on day 84 but did not differ (P > or = 0.05) between cattle on soil and on pond ash pens at any sampling period. The prevalence of the pathogen on hides and in feedlot surface material (FSM) also decreased (P < 0.0001), with no effect of soil or pond ash surface (P > or = 0.05). Similarly, levels of E. coli in FSM did not differ (P > or = 0.05) at any sampling period, and there were no clear trends for survival differences of E. coli O157:H7 or E. coli in FSM between pond ash and soil surfaces, although E. coli populations survived at 5.0 log CFU/g of FSM on the pen surfaces 6 weeks after the cattle were removed. These results indicate that housing cattle on pens surfaced with pond ash versus pens surfaced with soil does not affect E. coli O157:H7 in cattle or their manure.

Nutritional and management methods to decrease nitrogen losses from beef feedlots1

Nitrogen losses from open beef feedlots are a concern. Methods that decrease volatilization losses will lead to greater manure N, which is likely to be beneficial in open lot beef operations. Twelve or more pens were dedicated to N research whereby N intake, retention, and excretion were quantified and a mass balance conducted using manure, runoff, soil balance, and loss quantities. The objective was to decrease N volatilization losses or increase manure N or both. Dietary CP affects N excretion and N volatilization losses. Four experiments across 2 yr compared industry average CP (13%) to diets that were phase-fed to not exceed protein requirements (12.1 to 10.9%). Phase-fed cattle excreted 12 to 21% less N (P < 0.01), and N volatilization losses were reduced 15 to 33% (P < 0.01). In 2 other experiments, phase-fed diets were formulated to recycle undegradable intake protein. Steer G:F was similar (P = 0.18) or improved (P = 0.09), whereas N excretion and N volatilization losses tended to be reduced (P < 0.11) and N in manure was not affected (P > 0.35) compared with cattle fed 13% CP. Feeding less protein did not affect manure N, indicating manure N from open lots is related to other factors. A series of experiments evaluated increasing OM on the pen surface to increase N in manure. Feeding less digestible diets using fiber increased manure N (P < 0.01) and decreased (P < 0.10) N volatilization losses in 2 experiments conducted from November to May, but did not affect (P > 0.30) manure N or volatilization losses during 2 summer experiments. Adding bedding (i.e., OM) increased manure N in the winter as well. Another method evaluated was increasing pen cleaning frequency, which decreased N volatilization losses by 19 to 44% and increased manure N by 26 to 41% across 3 experiments. Other methods, such as acidifying manure by manipulating dietary cation anion difference, clinoptilite zeolite clay addition, and feeding different amounts of by-products had variable impacts on N volatilization losses. No treatments markedly affected runoff N, which is <5% of excreted N. Dietary protein affects N volatilization losses but not manure N. Other factors, such as OM on the pen surface, affect manure N. Cleaning manure frequently, which decreases exposure of manure N to air, decreases volatilization losses. Treatments should be evaluated across seasons due to seasonal effects.

Water spray cooling during handling of feedlot cattle

Activities involved in receiving or working (e.g., sorting, dehorning, castration, weighing, implanting, etc.) of feedlot cattle cause an increase in body temperature. During hot weather the increased body temperature may disrupt normal behaviors including eating, which can be especially detrimental to the well-being and performance of the animals. Sprinkle cooling of animals has been successfully employed within the pen; however, added moisture to the pens' surface increases odor generation from the pen. A study was conducted to investigate the effectiveness of a single instance of wetting an animal within the working facility instead of in the pen, which could potentially provide extra evaporative cooling to offset the added heat produced by activity. Sixty-four cross-bred heifers were assigned to one of eight pens on the basis of weight. On four separate occasions during hot conditions (average temperature 28.2 ± 1.9°C, 29.1 ± 2.0°C, 28.9 ± 3.0°C, and 26.8 ± 1.6°C; with the temperature ranging from 22.6 to 32.5°C during the trials), the heifers were moved from their pens to and from the working facility (a building with a scale and squeeze chute located 160-200m away). While in the squeeze chute, four of the pens of heifers were sprinkle cooled and the remaining four pens were worked as normal. The heifers that were treated had a body temperature that peaked sooner (31.9 ± 0.63min compared to 37.6 ± 0.62) with a lower peak body temperature (39.55 ± 0.03°C compared to 39.74 ± 0.03°C), and recovered sooner (70.5 ± 2.4min compared to 83.2 ± 2.4min). The treated animals also had a lower panting score, a visual assessment of level of cattle heat stress (1.1 ± 0.2 compared to 1.16 ± 0.2). The behavior measurements that were taken did not indicate a change in behavior. It was concluded that while a single instance of wetting an animal within the working facility did not completely offset the increase in body temperature, it was beneficial to the animals without needing to add water to the pen surface, thus reducing the potential for odor generation.

Chemical Composition of Pen Surface Layers of Beef Cattle Feedyards

The biological, physical, and chemical characteristics of beef cattle feedyard pen surfaces may affect nutrient transformations and losses to the atmosphere, ground water, or surface water. Feedyard pen surfaces can typically segregate into 3 or 4 layers. The purpose of this study was to determine if there were seasonal, within-pen location, days-on-feed, or urine effects on the chemical composition of the pen surface layers of feedyards. Samples were collected from 5 locations in 9 pens at 3 feedyards in each season and were analyzed for gravimetric water, pH, electrical conductivity (EC), nitrate + nitrite-N (NOx-N), ammonia + ammonium-N (NHx-N), N, C, and P. The percentage of water increased (P < 0.01) with depth among the manure layers and decreased in the soil. The pH of the manure layers increased with depth (P < 0.01) from approximately 7.6 to 8.2. The EC of the manure layers was greater (P < 0.01) than the EC of the soil layer, whereas the NOx-N concentration was greater (P < 0.01) in the soil layer. The NHx-N concentrations were lowest in the soil layer (P < 0.01). Total C and N concentrations decreased (P < 0.01) with sample depth. The composition of the layers was affected by season and location within the pen. Recent urine deposition did not affect the lower layers. The NHx-N concentration of the layers increased with days on feed. The differences in the chemical and physical properties of the layers in a feedlot pen may potentially affect nutrient losses to the atmosphere and to groundwater.

Performance of a Dispersion Model to Estimate Methane Loss from Cattle in Pens

Accurate measurements of enteric methane (CH(4)) emissions from cattle (Bos taurus) are necessary to improve emission coefficients used in national emissions inventories, and to evaluate mitigation strategies. Our study was conducted to evaluate a novel approach that allowed near continuous CH(4) measurement from beef cattle confined in pens. The backward Lagrangian Stochastic (bLS) dispersion technique was used in conjunction with global position system (GPS) information from individual animals, to evaluate CH(4) emissions from pens of cattle. The dispersion technique was compared to estimates of CH(4) production using the SF(6) tracer technique. Sixty growing beef cattle were fed a diet containing 60% barley silage (dry matter basis) supplemented with either barley (Hordeum vulgare L.) grain or corn (Zea mays L.) distillers dried grains. The results show that daily CH(4) emissions were about 7% lower for the dispersion technique than for the tracer technique (185 vs. 199 g CH(4) animal(-1) d(-1)). The precision of the dispersion technique, relative to the SF(6) tracer technique, expressed by the Pearson coefficient was 0.76; the relative accuracy given by the concordance coefficient was 0.69. The bLS dispersion technique was able to detect differences (P < 0.05) due to diet and has the added advantage of measuring the pattern of CH(4) production during the 24-h period, with emissions ranging from 161 to 279 g CH(4) animal(-1) d(-1). Configuring the cattle as point sources resulted in more accurate CH(4) emissions than assuming a uniform area release from the pen surface. The results indicate that the bLS dispersion technique using cattle as point sources can be used to accurately measure enteric CH(4) from cattle and to evaluate the impact of dietary mitigation strategies.

Nutrient Accumulation below Cattle Feedlot Pens in Kansas

Waste excreted on cattle (Bos taurus) feedlot pens is a source of N and other nutrients that could potentially leach into soil and negatively impact local groundwater quality. Analyses of soil chemical and physical properties beneath active open air feedlot pens were conducted at four Kansas locations to determine nutrient accumulation. Results were compared to estimated nutrient deposition, and remediation implications were considered. The surface concentrations of NH(4)-N, organic N, organic C, Cl(-), and extractable P were elevated at the surface and rapidly decreased with depth to 1.0 m. Ammonium N in the top 0.25 m ranged from 8000 to 375 mg kg(-1) but decreased below background (5.6 mg kg(-1)) at 1.0 to 1.3 m. Organic N in the top 0.25 m ranged from 22,000 to 500 mg kg(-1) and was the largest N source. At three of four feedlots, NO(3)-N was below background concentration (4.1 mg kg(-1)) for the entire profile whereas one feedlot had a >75 mg kg(-1) increase from the background concentration in the top 1.0 m. Considering expected nutrient deposition onto the pen surface only a fraction of the nutrients were found beneath feedlot pen surfaces. While in use, these feedlots do not appear to have a high potential for groundwater contamination from NO(3)-N leaching. However, if they were to become inactive NO(3)-N may increase and could leach into groundwater. Upon closing of the feedlots, the land could be largely remediated by removing the top 0.25 m of pen surface, a zone holding 48% of total profile N.

Modification of PEN Surface with Ar Plasma Treatment using ICP-CVD System

not Available.

Dynamic Contact Performance of Rubber Materials for Designing Wiper Blades

A printer assembly consisting of a pen, wiper with two blades, and wiper blade holder is investigated in this study. The two wiper blades press onto the pen surface via proper dimension interference, while wiping across the pen at a certain speed. A finite element model (FEM) was set up with ANSYS-LSDYNA. The hyper-elastic rubber wiper blades are described by Christensen’s model with n = 1 for the strain energy density function. Dynamic contact forces between the wiper blades and the pen, number of contacts, and the duration of the wiper blades jumping over the pen are numerically simulated. Effects of the mechanical properties of the rubber materials, i.e., the coefficient of the Christensen’s model, C10, on the dynamic contact performance are investigated. The wiper blades are found to periodically touch and jump off from the pen. For the contact between the front blade and the pen, results show that the average contact forces and the number of the contact will increase with C10, and for the back wiper blade there exist the same conclusions, except that the jumping duration of the back wiper blade does not decrease steadily, but shows a minimum. These results suggest that a new design with two curved sides of the blade tip could be beneficence.

Effects of shade and sprinklers on performance, behavior, physiology, and the environment of heifers

The objective was to measure effects of cooling technique (shade vs. water sprinklers) on performance, behavior, physiology, and the environmental effect of 40 Holstein heifers housed in drylot corrals during the hot summer months. The experiment was a replicated crossover design with four 21-d periods and 2 treatments: 1) shades installed in the front half of the pen or 2) sprinklers, which applied water to the pen surface at 2-h intervals from 1100 to 1900h. Animal performance measures were dry matter intake, average daily gain, and feed efficiency (gain:feed). Behavioral measures, elimination patterns, and corral spatial distribution were measured in 5-min scan frequencies over four 24-h periods. Physiological measures were rectal temperature, respiration rate, urinary urea N, and blood urea N. Environmental measures were corral soil surface temperature and moisture, particulate matter, and surface NH3 volatilization; meteorological measures were also collected. Shaded compared with sprinkled heifers had increased dry matter intake (3.4%), increased average daily gain (14%), and increased feed efficiency (11%). Heifers in shaded vs. sprinkler treatments had decreased respiration rates (13%). Behavioral differences between the treatments varied by time of day. Heifers spent most time in either the shaded or sprinkled areas of their corrals (65.9 and 64.2%, respectively). Elimination behavior occurred predominantly at the front of the corral in close proximity to the feed bunks and additionally at the water trough in sprinkled corrals. Sprinkler treatment had a 31.7% greater average corral surface moisture than the shaded treatment. Corral surface temperature varied based on areas of surface moisture, shade location, and elimination concentration within the corral. Sprinkled corrals had less particulate matter emissions than shaded (25%), but NH3 emissions were 46% greater in sprinkler vs. shaded treatment. Overall, the use of shade in heifer corrals improved heifer performance and physiological measures, but sprinkler treatment had less NH3 emissions from corral surfaces under heat stress conditions. Both cooling techniques affected spatial distribution and behaviors of the heifers, which affected pen usage and surface characteristics.

Physical and Chemical Properties of Feedlot Pen Surfaces Located on Moderately Coarse– and Moderately Fine–Textured Soils in Southern Alberta

Southern Alberta has the highest density of feedlot cattle in Canada, and there is a concern that leaching of water and contaminants may be greater for feedlots located on coarser-textured than finer-textured soils. Our objective was to determine if infiltration and leaching were greater for a 4-yr-old feedlot located on a moderately coarse-textured (MC) soil compared with two feedlots located on moderately fine-textured (MF) soils (5- and 52-yr-old pens). Various soil physical properties of feedlot pen surfaces were measured, including field-saturated hydraulic conductivity (K(fs)) and near-saturated hydraulic conductivity at -0.9 and -3.9 cm water potential. Selected chemical properties of feedlot soil layers were measured, as well as the chloride content of the soil profile (0-100 cm). Mean K(fs), K(-0.9), and K(-3.9) values were not significantly (P > 0.10) greater at the MC site than the two MF sites, indicating no evidence of greater infiltration on coarser-textured soils. In addition, mean K(fs), K(-0.9), and K(-3.9) values of soils within feedlot pens at all three sites were significantly (P < or = 0.10) reduced by 46 to 78% compared with soil outside the pens. Depth of chloride accumulation was greatest at the 52-yr-old feedlot on MF soil (60-70 cm), followed by 4-yr-old feedlot on MC soil (40-50 cm) and 5-yr-old feedlot on MF soil (30-40 cm). Visual inspection determined that the black interface layer formed within 2 mo of cattle stocking at all three sites.

Understanding extraction and beam transport in the ISIS H− Penning surface plasma ion source

The ISIS H(-) Penning surface plasma source has been developed to produce beam currents up to 70 mA and pulse lengths up to 1.5 ms at 50 Hz. This paper details the investigation into beam extraction and beam transport in an attempt to understand the beam emittance and to try to improve the emittance. A scintillator profile measurement technique has been developed to assess the performance of different plasma electrode apertures, extraction electrode geometries, and postextraction acceleration configurations. This work shows that the present extraction, beam transport, and postacceleration system are suboptimal and further work is required to improve it.

Nutrient balance of a commercial feedlot (2008)

The ability to develop nutrient balance for a livestock operation is important for maintaining a long-term sustainable production system and for compliance with current and future environmental regulations. Producers invest considerable financial resources in farm inputs, primarily feed and livestock. When animals leave the farm, they retain a portion of the feed nutrients they consumed, but the majority of consumed nutrients are excreted. Once excreted, certain compounds in the manure volatilize, which lowers the manure nutrient content and diminishes economic value of the manure as fertilizer. In addition, these volatile compounds can create air quality concerns. Operations designated as concentrated animal feeding operations must develop nutrient management plans to provide documentation that the manure produced will be applied at agronomic rates for environmental protection. Understanding the nutrient balance of a livestock operation is critical in developing whole-farm manure management plans. Objectives of this experiment were to determine the nutrient balance of a commercial feedlot and measure amounts of recoverable nitrogen and phosphorus from the feedlot pen surface.

Incidence and Persistence of Zoonotic Bacterial and Protozoan Pathogens in a Beef Cattle Feedlot Runoff Control–Vegetative Treatment System

Determining the survival of zoonotic pathogens in livestock manure and runoff is critical for understanding the environmental and public health risks associated with these wastes. The occurrence and persistence of the bacterial pathogens Escherichia coli O157:H7 and Campylobacter spp. in a passive beef cattle feedlot runoff control-vegetative treatment system were examined over a 26-mo period. Incidence of the protozoans Cryptosporidium spp. and Giardia spp. was also assessed. The control system utilizes a shallow basin to collect liquid runoff and accumulate eroded solids from the pen surfaces; when an adequate liquid volume is attained, the liquid is discharged from the basin onto a 4.5-ha vegetative treatment area (VTA) of bromegrass which is harvested as hay. Basin discharge transported E. coli O157, Campylobacter spp., and generic E. coli into the VTA soil, but without additional discharge from the basin, the pathogen prevalences decreased over time. Similarly, the VTA soil concentrations of generic E. coli initially decreased rapidly, but lower residual populations persisted. Isolation of Cryptosporidium oocysts and Giardia cysts from VTA samples was infrequent, indicating differences in sedimentation and/or transport in comparison to bacteria. Isolation of generic E. coli from freshly cut hay from VTA regions that received basin discharge (12 of 30 vs. 1 of 30 control samples) provided evidence for the risk of contamination; however, neither E. coli O157 or Campylobacter spp. were recovered from the hay following baling. This work indicates that the runoff control system is effective for reducing environmental risk by containing and removing pathogens from feedlot runoff.

Effect of sprinkling on feedlot microclimate and cattle behavior

Experiments were conducted to evaluate strategies designed to reduce heat stress of cattle. In the first experiment, cattle were sprinkled for 20 min every 1.5 h between 1000 hours and 1750 hours (WET) versus not sprinkled (DRY). In a second experiment, treatments consisted of: (1) control, no water application; (2) water applied to the pen surfaces between 1000 hours and 1200 hours (AM); and (3) water applied to pen surfaces between 1400 hours and 1600 hours (PM). In both experiments, sprinkling lowered (P < 0.05) mid-afternoon temperatures. In the first experiment, relative humidity (RH) of WET versus DRY pens differed (P < 0.05) and averaged 72.4 and 68.9%, respectively. The average temperature-humidity index (THI) in WET pens was 0.5 units lower (P < 0.05), than the THI in DRY pens. In the second experiment, RH in sprinkled pens was also greater (P < 0.05) than RH in control (CON) pens However, THI differed (P < 0.05) among treatments, being 81.5, 80.9, and 80.3, respectively for CON, AM, and PM. Pens with sprinklers had a larger percentage of steers in areas where sprinkling took place, even on days when sprinkling had not occurred. Based on differences in percentage of cattle panting in sprinkled and non-sprinkled treatments, sprinkling was found to have a positive effect on cattle feeding area microclimate and to reduce the susceptibility of cattle to hyperthermia. However, cattle acclimatization to being sprinkled can result in slight hyperthermia even during cooler days when sprinkling would normally not be utilized.

Growth performance and intestinal morphology responses in early weaned pigs to supplementation of antibiotic-free diets with an organic copper complex and spray-dried plasma protein in sanitary and nonsanitary environments1

The objective of this study was to determine the effects of addition of spray-dried plasma protein (SDPP) and Cu to nonmedicated diets on growth performance and intestinal morphology in weaned pigs reared in sanitary or nonsanitary environments. Weanling pigs (n = 192, 18 +/- 2 d of age, 6.0 +/- 0.2 kg of BW) were assigned to 8 treatments arranged factorially, including 2 dietary levels of SDPP (0 or 6% for the initial 10 d), 2 levels of added dietary Cu (0 or 200 ppm for the entire 35-d experiment), and 2 pen sanitation conditions (sanitized or nonsanitized before pig placement). The nonsanitary pen condition was created by 3 applications of swine manure slurry to all pen surfaces in 1 room and not washing or disinfecting. In an identical adjacent room, sanitary pens were washed and disinfected before weaning. There were 4 pigs per pen, and feed and water were available ad libitum. Growth performance was determined at the end of each diet formulation phase (d 10, 20, and 35 after weaning). On d 10, 1 pig per pen was euthanized, and cross sections of duodenum, jejunum, and ileum were collected for microscopic assessment of mucosal morphology. During the initial postweaning period, SDPP, and Cu supplementation improved ADG and ADFI (P < 0.001). A trend for an interaction of sanitation x dietary SDPP (P = 0.07) was observed for G:F, with a positive response to the supplement in nonsanitary pens but no response in sanitary pens. There were no interactions of SDPP and Cu for any performance variables (P > 0.30). By d 35, there were no main or interaction effects of treatment on ADG or G:F (P > 0.17). Pen sanitation condition produced morphological effects, with shorter villous length and less crypt depth observed in each intestinal segment for pigs reared in the nonsanitary pens (P < 0.05), but these effects must be considered conditional based on the potential confounding influence of separate nursery rooms. In the duodenum, reduced crypt depth with Cu supplementation (P = 0.01) and a tendency for greater villous length with SDPP supplementation (P = 0.09) were observed. In this study, SDPP and Cu supplementation improved pig growth performance during the initial 10-d postweaning. These modifications to nonmedicated diets acted independently with regard to their impacts on postweaning performance and, therefore, could have additive effects.