Modern swine heat production is 6-41% higher than documented in engineering standards. This higher heat production indicates that the ideal thermal neutral temperature may have changed. Thermal comfort is critical to maximise production and well-being of modern swine. Measurements of posture, skin temperature, and ear temperature profile changes with air temperature were evaluated for three modern pig genetic lines. A total 180 nursery pigs (30 animal per sire e 3 breeds: Duroc, Landrace, and Yorkshire) were acutely exposed to each of seven temperatures (20 degrees C, 22.5 degrees C, 25 degrees C, 27.5 degrees C, 30 degrees C, 32.5 degrees C, 35 degrees C) over a 13-day period. Time-lapse images were taken every 5-min of 10 pens with 18 pigs each to document posture and floor space. Individual thermal images were captured on 12 pigs/sire-breed e 36 total at each temperature. Thermal images were used to assess trunk and ear surface temperatures. Temperatures along the centerline of the ear were also evaluated for each pig 12 pigs/sire line e 36 total. Changes in the average trunk surface temperature were fit to two separate linear regression equations e above and below the standard temperature of 27.5 degrees C. The two regression lines were solved simultaneously to estimate the thermoneutral temperature. The threshold temperatures were determined to be 26.1 degrees C for Duroc sired pigs, 27.9 degrees C for Yorkshire sired pigs and 28.8 degrees C for Landrace sired pigs. Based on the results of this study the standard set point of 27.5 degrees C is appropriate for nursery pigs. Published by Elsevier Ltd on behalf of IAgrE.

Mineral and organic salts from beef manure in runoff alter the resistivity properties of soil and water. Typically, holding ponds are used to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, leaks from holding ponds are detected by installing a series of monitoring wells at strategic locations near the pond to intercept any contaminants that reach groundwater. Monitoring wells are expensive to install, costly to sample, generate information that is difficult to interpret and can only warn of a leak after contamination of groundwater has already occurred. A method was developed to continually measure the soil quality around the perimeter of holding ponds. When a change is detected, a message can be sent to facility managers to alert them of potential problems. However, the analysis of the data generated by this new method can be difficult to interpret. A protocol was developed that has 1) a site-calibration method to tailor analysis for most geologic and geographic settings, 2) establishes statistical-based thresholds for detecting changes in soil and groundwater quality, 3) allows for detection sensitivity to be scaled, 4) provides a filter for reducing false-positive leak detections and 5) provides a consistent framework for regulatory reporting. The protocol is designed to be incorporated into automated software that can immediately notify pond managers of potential problems using currently available telecommunication technology.

Heat stress in cattle results in decreased feed intake, lower daily gain, and potentially death in susceptible animals under intense conditions. A study was carried out during the summer of 2013 at the USDA-ARS U.S. Meat Animal Research Center feedlot evaluating the impact of shade on environmental conditions and cattle performance. A novel twotiered shade was used in half of the 14 pens, each holding 30 animals. The shades were designed to reduce solar heat load by 40% to 60% and to provide traveling shade across the pen, providing varied amounts of shade area as well as varied solar reduction potential. The objective of this study was to determine if the shade was effective at improving performance (evaluated as average daily gain, feed intake, and feed to gain ratio) and reducing environmental conditions that cause heat stress. A group of mixed-breed cattle with varied genetics including both Bos taurus and Bos indicus were selected, penned on the basis of sex, and blocked by color. Production parameters of pen feed usage were measured daily, and individual body weights were taken monthly. Environmental conditions including air temperature, relative humidity, wind speed, ground temperature, and black globe temperature with and without shade were measured. Solar load on the pens was reduced when shade was provided, with both ground temperature and black globe temperature showing reductions. Cattle showed nominally better performance; however, no significant differences were found in gain or feed intake. Panting scores were significantly lower with shade provided; slopes of cattle respiration rate versus ambient temperature were significantly lower with shade during the afternoon period.

Heat stress has a significant impact on all livestock and poultry species causing economic losses and animal well-being concerns. Providing shade is one heat-abatement strategy that has been studied for years. Material selected to provide shade for animals greatly influences the overall stress reduction provided by shade. A study was conducted to quantify both the environment and animal response, when cattle had no shade access during summertime exposure or were given access to shade provided by three different materials. A total of 32 Black Angus heifers were assigned to one of the four treatment pens according to weight (eight animals per pen). Each pen was assigned a shade treatment: No Shade, Snow Fence, 60% Aluminet Shade Cloth and 100% Shade Cloth. In the shaded treatment pens, the shade structure covered ~40% of the pen (7.5 m2/animal). Animals were moved to a different treatment every 2 weeks in a 4×4 Latin square design to ensure each treatment was applied to each group of animals. Both environmental parameters and physiological responses were measured during the experiment. Environmental parameters included dry-bulb temperature, relative humidity, wind speed, black globe temperature (BGT), solar radiation (SR) and feedlot surface temperature. Animal response measurements included manual respiration rate (RRm), electronic respiration rate (RRe), vaginal temperature (body temperature (BT)), complete blood count (CBC) and plasma cortisol. The environmental data demonstrated changes proportional to the quality of shade offered. However, the animal responses did not follow this same trend. Some of the data suggest that any amount of shade was beneficial to the animals. However, Snow Fence may not offer adequate protection to reduce BT. For some of the parameters (BT, CBC and cortisol), 60% Aluminet and 100% Shade Cloth offers similar protection. The 60% Aluminet lowered RRe the most during extreme conditions. When considering all parameters, environmental and physiological, 60% Aluminet Shade Cloth offered reductions of BGT, SR, feedlot surface temperature and the best (or equal to the best) overall protection for the animals (RRe, RRm, BT, blood parameters).

The individual abstracts for this session are available to read in the PDF.

Mineral and organic salts from beef manure contained in precipitation runoff from feedlot pen surfaces can alter the conductivity properties of soil and water receiving it. Typically, holding ponds are constructed to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, ponds are monitored by installing monitoring wells at strategic locations to evaluate the impact of these ponds on the environment. Monitoring wells are expensive to install, costly to sample and the information received is subject to ambiguous interpretation. Researchers from USDA-ARS U.S. Meat Animal Research Center have combined efforts and resources with the Nebraska Cattlemen, the Nebraska Department of Environmental Quality (NDEQ), and AgraTek LLC, to evaluate electronic monitoring of subsurface soils near holding ponds used to contain runoff from beef cattle feedlots. A three year study summarized data from two feedlots and concluded that resistivity array systems were able to adequately measure subsurface dynamics and to alert operators of changes that exceeded nominal operation. Subsequently, two NDEQ provisionally approved systems were installed at a University of Nebraska research site. Unlike previous test installations, each of these new sites required non -collinear installations. This report discusses the theoretical development and testing of non -collinear arrays which proved to be a viable approach to unique array geometries necessitated by feedlot designs.

Beef cattle manure can serve as a valuable nutrient source for crop production. However, emissions of volatile organic compounds (VOCs) following land application may pose a potential off-site odor concern. This study was conducted to evaluate the effects of land application method, N application rate, soil moisture content, and time since manure application on VOC emissions. Manure from cattle fed a diet containing 30% wet distillers grains was applied to a cropland area at rates required to meet the 0.5, 1, or 2 year N requirement for corn. Land application methods included surface-applying manure (i.e., no tillage) or incorporating manure using disk tillage. The effect of soil moisture content on VOC emissions was determined by adding water to the experimental plots approximately 24 h after manure application. Volatile sulfur compounds (i.e., dimethyl disulfide and dimethyl trisulfide), isovaleric acid, and butyric acid contributed 43.4%, 14.0%, and 13.9%, respectively, of the total measured odor activity value (OAV). Emissions of each of the principal VOC odor compounds were reduced by manure incorporation. In general, no significant differences in VOC measurements of volatile fatty acids (VFAs) and aromatic compounds were found among varying manure application rates. However, an increase in emissions of volatile sulfur compounds resulted from increased manure application. Measurements of VFAs and aromatic compounds usually decreased and sulfide emissions increased following the application of water. Application method, N application rate, soil moisture content, and time since application may all influence VOC emissions following land application of cattle manure.

The individual abstracts for this session are available to read in the PDF.

Monitoring wells are installed to intercept contaminants inadvertently discharged from inground structures designed to retain salt-affected wastewaters; however, several difficulties with collection and data interpretation limit their effectiveness. Therefore, improved monitoring methods are needed. The objective of this study was to evaluate the effectiveness of resistivity array technology as an early warning system to monitor for unintended basin discharge. Subsurface resistivity arrays were installed at two Nebraska sites: a beef cattle feedyard located at the U.S. Meat Animal Research Center, Clay Center, Nebraska (FyA) and a commercial cattle feeding operation (FyB). Monitoring well data did not identify any unintended discharge events during the study period. However, the resistivity array (RA) system detected a discharge event that was localized in the non-saturated zone adjacent to the pond at FyB within one day following a precipitation event. Monitoring the unsaturated portion allows the RA system a capacity beyond traditional monitoring wells, which can only intercept discharge carried in groundwater. Also, the RA system effectively measured a larger area (i.e., a virtual curtain) compared to the point measure typical of monitoring wells. Therefore, RA technology provides broader coverage and is more tolerant to placement issues for intercepting discharge. Finally, the capacity to automate the RA system provides a means to continuously monitor unintended subsurface discharge from runoff holding ponds. This continuous monitoring system is more likely to detect discharge events than the bi-annual sampling typically required for monitoring wells. Automatic and continuous monitoring provides feedyard operators options to better manage environmental impacts associated with runoff holding ponds.

Radio Frequency Identification (RFID) systems are widely used in production livestock systems for identification, traceability assurance, and animal registration. An RFID system was implemented and evaluated for use in a four-compartment, two-tier, environmental preference chamber (EPC) to detect hens transiting between compartments. Eight RFID antennae were located near the passages between compartments and each hen wore an RFID tag on one of its legs. The RFID system’s performance was assessed by determining detection ranges in a controlled test and by comparing the number of entries into and duration in each compartment as detected by the RFID system to manual assessment of recorded video. The RFID system detection range was revealed to cover a radius of approximately 29cm from the antenna, excluding a portion of the compartment furthest from the antenna. During a choice-test study, successful detection rates based on duration of stay in compartments were 91.0±2.6% (mean±SD) for trials with groups of birds, and 85.8±8.0% for trials with individual birds. Based on number of entries into compartments, successful detection rates were 62.6±11.2% for trials with groups of four birds, and 51.3±18.4% for trials with individual birds. Sources of entry misdetection included: (i) RFID tag being out of the detection range during sampling; (ii) conflicts caused by multiple RFID tags within the same detection zone; and (iii) visits of duration less than the RFID antenna scan interval. The delay between hen entry and RFID system detection averaged 42.3±35.7s and 6.4±5.2s in trials with individuals and with groups, respectively. Detection times were within the antenna scanning interval of 15s (a hen entered a compartment and was immediately detected by the next antenna scan) in 60.3% of the events with individuals and 98.1% of the events with groups. Despite the difference between detected and actual entries (P=0.008 [groups]; P=0.05 [individuals]), no significant differences were found between total duration of compartment occupancy over a 24h test period or average compartment visit duration, as calculated from RFID data and video observations. The RFID system was suitable for characterizing the amount of time birds spent in each EPC compartment, but not reliable for determining number of entries into a compartment.

Feeding behavior contains valuable information that can be useful for managing livestock, identifying sick animals, and determining genetic differences within a herd. The objectives of this work were to determine the minimum meal interval and to assess changes in feeding behavior of feedlot heifers when exposed to various temperatures with and without access to shade. Feeding behavior data from feedlot cattle with and without access to shade were evaluated. Prior to evaluating feeding behavior data, the time between two eating events that should be considered a single meal (minimum meal interval) was determined. The length of this minimum meal interval impacts the interpretation of meal data. The minimum meal interval was first determined by analyzing feeding behavior data to determine the number of meals, average meal length, and total time spent eating at minimum meal intervals ranging from 1 to 60 min. These data were evaluated using rate of change based on interval differencing. A subsequent analysis identified the inflection point of the rate of change graph. A minimum meal interval of 10 min for finishing feedlot cattle was determined using this method. Feeding behavior data from 256 feedlot heifers (of four different breed types) were evaluated over two summer periods (128 heifers each year). Cattle were penned in one of 16 pens (eight shaded and eight unshaded). Individual feeding behavior data were collected every 30 s throughout the six-week summer period. Cattle decreased the time spent eating, average meal size, and number of meals as the THI increased. In addition, cattle provided with shade spent more time eating, with longer meal lengths over all THI categories.

A laboratory study was conducted to evaluate the effects of pen location, moisture, and temperature on emissions of volatile organic compounds (VOC) from surface materials obtained from feedlot pens where beef cattle were fed a diet containing 30% wet distillers grain plus solubles. Surface materials were collected from the feed trough (bunk), drainage, and raised areas (mounds) within three feedlot pens. The surface materials were mixed with water to represent dry, wet, or saturated conditions and then incubated at temperatures of 5, 15, 25 and 35 degrees C. A wind tunnel and gas chromatograph-mass spectrometer were used to collect and quantify emissions of eight volatile fatty acids (VFAs), five aromatics and two sulfur-containing compounds. Pen location significantly (P <0.05) affected measurements of 10 of the VOC with the largest values occurring for materials collected near the mound area. The largest VFA and aromatic emissions resulted for the dry moisture condition while wet and saturated conditions produced the largest sulfide emissions. Temperature affected emission of each VOC except indole, with values generally increasing as temperature increased. Odour activity value (OAV), which was the ratio of measured concentration of a single compound normalised to the odour threshold for that compound, was calculated for each compound. Four VFAs contributed 7.5% of the total OAV but only one aromatic, 4-methylphenol, was a major contributor to total OAV at 2.5%. In comparison, sulfide compounds contributed 87.3% of the total OAV. This research shows VOC emissions are affected by pen location, moisture condition, and temperature. Published by Elsevier Ltd on behalf of IAgrE.

Beef cattle manure can serve as a valuable source of nutrients for crop production. However, emissions of volatile organic compounds (VOCs) after land application may pose an odor nuisance to downwind populations. This study was conducted to evaluate the effects of land application method, diet, soil moisture content, and time since manure application on VOC emissions. Manure was collected from feedlot pens where cattle were fed diets containing 0, 10, or 30% wet distillers grains with solubles (WDGS). Land application methods included surface-applying manure (i.e., no-tillage) or incorporating manure using disk tillage. The effects of soil moisture content on VOC emissions was determined by adding water to each of the plots approximately 24 h after manure application. Isovaleric acid, butyric acid, and 4-methylphenol contributed 28.9, 18.0, and 17.7%, respectively, of the total measured odor activity values. In general, the largest emissions of volatile fatty acids and aromatics were measured during the initial collection periods on the no-tillage plots under dry soil moisture conditions. Emissions of volatile fatty acids and aromatics were reduced after water additions because these compounds were stored in the soil-water matrix rather than released into the atmosphere. In contrast, sulfide emissions generally increased with the addition of the water, especially on the plots containing manure from the 30% WDGS diet. Sulfur content of manure increases with higher percentages of WDGS feed stock. Application method, diet, soil moisture content, and time since application should be considered when estimating VOC emissions.

Heat production from modem pigs has been determined to be significantly higher than previously reported. This increase in heat production changes the thermal needs of modem growing pigs. A study was designed to evaluate using surface temperatures as a method of determining heat tolerance of growing pigs based on changes in thermal images captured at different temperatures. Thermal images were taken of one hundred sixty group-penned pigs (26.9-62.2 kg) and twenty individual pigs (31.1-57.2 kg) on seven selected days covering a temperature range of 21.3 degrees C-36.6 degrees C. The thermal images were analysed to determine either average temperature (individual pigs) or high and low temperatures (group penned pigs). Surface temperatures were significantly affected by ambient temperature and response equations were developed. Breakpoint analysis revealed a threshold, thought to equate to the maximum value of the thermal neutral zone, ranging between 17.4 degrees C and 23.2 degrees C. It was concluded that thermal images could be successfully used to evaluate the thermal needs of pigs, and that further experiments need be conducted to validate thresholds as determined by thermal images. Published by Elsevier Ltd on behalf of IAgrE.

Feeding behavior and time spent eating contains valuable information that can be used for managing livestock, identifying sick animals, and determining genetic differences within a herd. Individual animal feeding behavior, in a commercial-sized pen, was recorded using radio-frequency identification (RFID) technology and a series of multiplexers. Data were collected on 960 pigs (mixed barrows, 406 and gilts, 600) over 4 grow-out periods. The animals entered the facility at 24.6 +/- 5.4 kg (mean +/- standard deviation) at approximately 65 days of age and exited the facility at 101.4 +/- 13.8 kg (between 116 and 133 days later). Time spent at the feeder was analyzed for the effects of days on feed, sex, weight gain, and health effects. The amount of time spent at the feeder averaged 68.8 min day(-1) pig(-1) over the grow-out period, and increased from the day the pigs enter the facility (24.0 +/- 1.6 min day(-1) pig(-1); mean standard error) until plateauing at approximately 40 days later (76.7 +/- 2.4 min day(-1) pig(-1); age similar to 105 days). After the plateau, barrows spent 13.6 more minutes per day at the feeder than gilts. Pigs classified as 'high gaining' (79.2 +/- 5.1 min day(-1) pig(-1)) spent more time at the feeder than pigs classified as either 'normal' (72.6 +/- 2.6 min day(-1) pig(-1)) or 'low gaining' (67.6 +/- 5.3 min day(-1) pig(-1)). This initial manuscript demonstrates the potential of utilizing feeding behavior or time spent eating as a method of managing animals. Published by Elsevier B.V.

Heat stress in cattle causes decreases in feed intake, growth, and efficiency. In extreme cases, heat stress can cause death of vulnerable animals. A simple shade can reduce the animal's radiant heat load by 30% or more. However, for most feedlots, adding shade structures to all pens is cost-prohibitive. The objective of this study was to determine how animals, with known risk factors (color, previous cases of pneumonia, condition score, and temperament) for heat stress, respond to having access to shade. Feedlot heifers (384 animals; 128 animals year(-1) for three years) of two breeds (Angus and Charolais) and two composite breeds (MARC I [1/4 Charolais, 1/4 Braunvieh, 1/4 Limousin, 1/8 Angus, and 1/8 Hereford] and MARC III [1/4 Pinzgauer, 1/4 Red Poll, 1/4 Hereford, and 1/4 Angus]) were selected and penned on the basis of weight and breed. Heifers were weighed and scored for condition and temperament every 28 days. Heat tolerance was accessed by measurements of respiration rate taken twice daily at 08:00 and 13:00 h on a preselected group of 64 animals. It was determined that shade lowered the respiration rate of all animals. In addition, shade had a greater impact on the Angus cattle than the Charolais cattle, with the two composite breeds (with dark red and tan hides) having an intermediate response. Access to shade did not improve weight gains of any of the breeds.

Abstract. This study investigated the effects of within pen location, moisture, and temperature on odor emissions from manure derived from diets containing 30% distillers grain. Pen surface material was collected from three within pen locations. Material was consolidated for each specific location. Approximately 6.0 kg of pen material from was mixed with water to represent dry, wet, and saturated conditions. Material was packed into pans and incubated at a specific temperature for four days. All compounds had greater emissions at 35 o C than at lower temperatures except indole. The greatest volatile fatty acid (VFA) and aromatic emissions occurred under dry conditions while wet and saturated conditions produced greater sulfide emissions. Generally, VFAs and aromatics are more soluble than sulfide compounds; therefore, when water was present, these compounds remained in solution. Sulfide contributed 87.3% of the total odor activity value (OAV) when averaged across all treatments. Wet conditions at the bunk and drainage area may consistently have redox potentials not favorable for DMDS and DMTS production. Wetting and dry cycles typical at the mound may have redox potentials during wet periods favorable for sulfide production and during dry periods have potential favorable for VFA and aromatic production. This may explain why the mound accounted for over half of the OAV. Sulfide contribution to the OAV is further illustrated by each within pen location, moisture content and temperature. Sulfide emissions dominated (i.e., > 75%) the other compounds with the exception of dry condition where the VFA, aromatic and sulfide contribution were evenly distributed.

Shade structures are often considered as a method of reducing heat stress in feedlot cattle during extreme summer conditions. Design and material selection present challenges to meet a range of criteria that include: cost, effectiveness, durability, low maintenance, and minimal interference with normal feedlot management. The design described in this paper integrates animal/shade response data collected over the last decade. Eight 10 m tall by 15.4 m long structures were installed at the USMARC feedlot. The north/south structures were fitted with four 15.4 m lengths of poly snow-fence. These structures provide an effective 50% shade coverage that tracks the sun during the day and offers up to 3 m2 of shade per head. Design considerations, construction materials and methods are presented as well as preliminary observations based on time-lapse photography of animal movements. * The mention of trade names of commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA. The USDA is an equal opportunity provider and employer.