Richard Gates | Iowa State University (original) (raw)

Papers by Richard Gates

Transactions of the ASABE, 2012

This work carried out a three-month experiment to study the transport, transformation, and fate o... more This work carried out a three-month experiment to study the transport, transformation, and fate of nitrogen (N) in two gas-phase ammonia mitigation biofilters using agricultural products (a mixture of wood chips and compost) as the packing media. Two nitrogen enriching steps and one nitrogen depleting step were included as a swing test. In the first nitrogen enriching step, a high ammonia inlet concentration (~70 ppm) was applied. The ammonia removal efficiencies reached 94%, and 73.5% to 86.6% of N-NH 3 was transformed into NH 4 +-N, NO 2-N, or NO 3-N. The nitrogen depleting step partially cleaned nitrogen compounds with limited disturbance to the media and restored ammonia removal efficiency for a short time. The second nitrogen enriching step used a lower (40 ppm) ammonia inlet concentration. Only 33.4% to 46.2% of NH 3-N was transformed into NH 4 +-N, NO 2-N, or NO 3-N in the media, and the ammonia removal efficiency fell quickly after ten days. The pH values in the biofilter media were high and changed only slightly during the test (8.5 to 8.2). The free ammonia concentration reached 784 mg L-1 in the media moisture. The nitrogen mass balance analysis showed that the NH 4 +-N, NO 2-N, and NO 3-N accumulated in the media accounted for 50% to 100% of the nitrogen captured from the inlet gas. The nitrification process was modeled as consecutive first-order reactions. The kinetic time constants of the two first-order reactions decreased with time and with accumulated nitrogen in the media, suggesting a decline of the nitrogen transformation rates. One very likely reason that caused the decrease of ammonia removal efficiency and kinetic time constants is the accumulated free ammonium in the biofilter media.

Field evaluation of integrates environmental controlers , Field evaluation of integrates environm... more Field evaluation of integrates environmental controlers , Field evaluation of integrates environmental controlers , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Livestock Environment VII, 18-20 May 2005, Beijing, China

Swine production represents an important economic and social activity in Brazil, however, its tra... more Swine production represents an important economic and social activity in Brazil, however, its traditional exploration is considered by the ambient institutions as an activity of great pollutant potential. The objective of this study was to compare ammonia level in the traditional slatted concrete floor system, a bedded system with wood shavings on top of the concrete floor, or a bedded system with rice hulls on top of the concrete floor. The study was conducted at the EMBRAPA Swine Research Station in Concordia, Santa Catarina, Brazil during August to November 2002. Significant differences among the treatments were observed; the concrete flooring system had the lowest ammonia levels, whereas both bedded systems shared fairly similar levels. However, these measured values in all the treatments were below the threshold level of 20 ppm.

Applied Engineering in Agriculture, 2003

This work describes an instrumentation and data acquisition system designed for a deep bed reacto... more This work describes an instrumentation and data acquisition system designed for a deep bed reactor used to cultivate Trichoderma longibrachiatum on wheat bran. The system allowed on-line measurements of substrate temperature, oxygen concentration within the reactor headspace, relative humidity and temperature of the inlet air, and inlet airflow rates while maintaining aseptic conditions and without disturbing the cultivation process. An error analysis for the instrumentation and data acquisition equipment was completed and provided insight into the reliability of the sensor readings. The collected data provided quantitative information about the reactor system dynamics which can be used to evaluate and apply environmental control schemes, gain knowledge on microbial growth characteristics, and develop and validate mathematical models describing heat and mass transfer interactions.

Applied Engineering in Agriculture, 2006

Right click to open a feedback form in a new tab to let us know how this document benefits you.

Tobacco greenhouse ventilation design thus involves ventilation for temperature control, and vent... more Tobacco greenhouse ventilation design thus involves ventilation for temperature control, and ventilation for moisture control. At any time during the day or night, one of these two ventilation requirements is larger than the other, and it is this larger requirement that must be met with a properly designed ventilation system. Ventilation is measured with volume of air moved in a time interval, typically cubic feet per minute (cfm).

Poultry production in subtropical and tropical regions faces many problems, one of which is the h... more Poultry production in subtropical and tropical regions faces many problems, one of which is the high air temperature causing thermal stress, particularly dangerous in high-producing birds. Thus, the negative effects caused by heat stress (HS) must be managed. The objective of this study was to evaluate the effects of four different levels of HS in viscera and tibia of pullets. A total of 648 chicks (Lohmann LSL Lite) were used in this study in two different phases. The pre-experimental phase (PEP) was from day 1 through 6 weeks of age. The birds were reared with three different environmental temperatures: thermal comfort, hot and cold. The experimental phase (EP) was conducted from the 7th to the 17th week. Pullets from each thermal environment of the PEP were submitted to: 20 °C, 25 °C, 30 °C, 35 °C. At the end of the 17th week of age 120 pullets were euthanatized and the organs, heart, liver, spleen and gizzard were weighed, as also their tibias. Effects of PEP, and its interactio...

Poultry Science, 2019

This study examined the effect of water-chilled perches on hen production and physiological respo... more This study examined the effect of water-chilled perches on hen production and physiological responses to induced molt during elevated temperatures. A total of 288White Leghorns at 82 wk of age were housed in 36 cages of 6 banks. Each bank was assigned to 1 of 3 treatments: cooled perches, air perches, and no perches. The hens were subjected to 2 heat episodes during their first laying cycle at week 21 to 35 and week 73 to 80, respectively. The hens were subjected to a 28 D nonfasted molting regimen starting at 85 wk of age. Cyclic heat of 32°C (6:00 am to 6:00 pm) was applied daily during the molting period. After molt, hens were returned to a layer diet and housed under thermoneutral condition. Two birds per cage were monitored for BW change during molt. Egg production was recorded daily. Feed utilization was measured during molt at 86 and 88 wk of age. Egg weight and eggshell traits were examined at 84 wk (pre-molt) and post-molt at 92, 96, and 104 wk of age. Rectal temperature an...

An ongoing project of monitoring ammonia (NH3) emissions from U.S. layer houses with two differen... more An ongoing project of monitoring ammonia (NH3) emissions from U.S. layer houses with two different housing and management schemes is reported in this paper. Ammonia and carbon dioxide concentration levels were collected bi-weekly from each house with portable monitoring units (PMUs). There exist substantial seasonal variations in NH3 emission from the layer houses. Specifically, daily mean NH3 concentrations in the manure belt house and the high-rise house ranged from 1 to 7 ppm and 9 to 108 ppm, respectively. The NH3 emission rates over the 9-month monitoring period (Feb. – Oct., 2002) averaged 7 mg/hr-hen or 58 g/d-500kg for the manure belt house and 43 mg/h-hen or 326 g/d-500kg for the high-rise house. Ammonia emission rates are higher in summer than in winter, although NH3 concentration may be much lower in summer. KEYWORDS- Ammonia, Emission rates, Ventilation rate.

Part of the Bioresource and Agricultural Engineering Commons The complete bibliographic informati... more Part of the Bioresource and Agricultural Engineering Commons The complete bibliographic information for this item can be found at

United States animal production systems are at the threshold of a major new method for daily mana... more United States animal production systems are at the threshold of a major new method for daily management of environmental control -- the integrated microprocessor-based environmental control system. Widespread adoption of this technology has the potential for dramatic improvement in production efficiencies through lower management costs, improved energy savings, and better feed conversion efficiencies. However, the technical problems of transient surge protection and appropriate mechanical backup systems have not been adequately addressed by the industry. The goals of this research were to identify the degree to which transient surge protection was being provided by current manufacturers, and to illustrate the implementation of microprocessor environmental control systems with mechanical backup. Transient open circuit over-voltage tests (ANSI/IEEE C62.41-1980) were performed on 16 environmental control units: a maximum of 800 V spike was applied to the power supplies, and up to 100 V...

Revista Brasileira de Engenharia de Biossistemas, 2020

RESUMO O Brasil é um dos principais produtores mundiais de carne de frango e de ovos, e para se m... more RESUMO O Brasil é um dos principais produtores mundiais de carne de frango e de ovos, e para se manter competitivo no mercado, novas metodologias vem sendo estudadas e implementadas a fim de se obter maior rendimento na produção, enfatizando-se o manejo, dieta, sanidade e ambiência. Neste sentido, o monitoramento e controle de variáveis relacionadas ao ambiente térmico e qualidade do ar são de extrema relevância. Ademais, o perfil do consumidor atual tem se mostrado cada vez mais exigente frente ao bem-estar animal diante da grande visibilidade desse conceito nos últimos anos, segundo o qual a procedência dos produtos consumidos são critérios de escolha no momento da compra. Na produção avícola industrial, um dos pontos cruciais para garantia de um ambiente confortável para as aves e, assim, boas respostas nos índices zootécnicos, consiste na escolha e dimensionamento correto do sistema de ventilação instalado nos galpões de criação. Diante disso, para alcançar melhor distribuição do fluxo de ar em aviários e atender as exigências internacionais de bem-estar e qualidade do ar, de acordo com os padrões de qualidade exigidos, esta revisão de literatura objetivou apresentar um levantamento dos principais sistemas de ventilação, bem como de sua aplicabilidade na avicultura brasileira, além de reportar o estado na arte nesse tema. Palavras-chave: Acondicionamento térmico. Aviário. Ventilação híbrida. Ventilação mecânica. Ventilação natural.

Transactions of the ASAE, 1998

uring the past four decades, a number of dairy scientists and engineers have conducted research i... more uring the past four decades, a number of dairy scientists and engineers have conducted research in the area of labor utilization in milking facilities. As a part of this research, they have conducted time and motion studies, developed labor saving equipment and proposed new methods of milking management which have greatly improved our knowledge of, and efficiencies in, the milking operation. Additionally, computer simulation models have been developed for a limited number of milking parlor configurations. Milking parlor configurations have evolved through the years into four basic types, whose desirability depends upon the requirements of the individual dairyman. Bickert (1980) suggested the most commonly used parlor configurations were the side opening, herringbone, polygon, and trigon. More recently, larger parlors (double-10 or larger) have included a parallel configuration (Thomas et al., 1994). Each parlor type can be equipped with varying degrees of automation depending on the management philosophy of the operator, the herd size and cow throughput requirements. All milking parlors have basic equipment requirements; i.e., milking system components, stalls, gates, doors, feeding equipment, udder hygiene equipment, and utilities. In addition, the parlor may be equipped with labor-saving devices such as: automatic detachers, crowd gates, automatic door and gate controls, automated feeders, feed bowl covers, back flushing, automatic teat dip application, and even computerized herd data and management systems. In general, the milking process follows a logical sequence: after parlor setup and holding pen loading, cows are brought into the parlor, prepared for milking, milkers are attached, milkers are detached after milking completion, post milking hygiene is administered, and the cows are released. Although miscellaneous tasks may be required during the milking process, the process itself is straightforward. As a result of ergonomic studies by Appleman and Micke (1973), Merrill and Thompson (1980), Bickert and Armstrong (1976), and Armstrong and Quick (1986), a number of work routines have been suggested to minimize the time and effort required by the operator to efficiently and consistently maintain high cow throughput. To assess the viability of a particular work routine, time and motion studies are conducted. During the past 40 plus years, a number of time and motion studies have been completed by dairy researchers such as:

Transactions of the ASABE, 2011

Poultry Science, 2018

Fitts' law models the relationship between amplitude, precision, and speed of rapid movements. It... more Fitts' law models the relationship between amplitude, precision, and speed of rapid movements. It is widely used to quantify performance in pointing tasks, study human-computer interaction, and generally to understand perceptual-motor information processes, including research to model performance in isometric force production tasks. Applying Fitts' law to an isometric grip force task would allow for quantifying grasp performance in rehabilitative medicine and may aid research on prosthetic control and design. We examined whether Fitts' law would hold when participants attempted to accurately produce their intended force output while grasping a manipulandum when presented with images of various everyday objects (we termed this the implicit task). Although our main interest was the implicit task, to benchmark it and establish validity, we examined performance against a more standard visual feedback condition via a digital force-feedback meter on a video monitor (explicit task). Next, we progressed from visual force feedback with force meter targets to the same targets without visual force feedback (operating largely on feedforward control with tactile feedback). This provided an opportunity to see if Fitts' law would hold without vision, and allowed us to progress toward the more naturalistic implicit task (which does not include visual feedback). Finally, we changed the nature of the targets from requiring explicit force values presented as arrows on a force-feedback meter (explicit targets) to the more naturalistic and intuitive target forces implied by images of objects (implicit targets). With visual force feedback the relation between task difficulty and the time to produce the target grip force was predicted by Fitts' law (average r 2 = 0.82). Without vision, average grip force scaled accurately although force variability was insensitive to the target presented. In contrast, images of everyday objects generated more reliable grip forces without the visualized force meter. In sum, population means were well-described by Fitts' law for explicit targets with vision (r 2 = 0.96) and implicit targets (r 2 = 0.89), but not as well-described for explicit targets without vision (r 2 = 0.54). Implicit targets should provide a realistic see-object-squeeze-object test using Fitts' law to quantify the relative speed-accuracy relationship of any given grasper.

Poultry Science, 2019

The objective of this study was to evaluate the effects of different environment conditions on pr... more The objective of this study was to evaluate the effects of different environment conditions on productive performance and surface temperatures of Japanese quail (Coturnix coturnix japonica) during the initial stage of laying. In environmental controlled chambers, the birds were subjected to different temperatures and air velocities at the feeder. A total of 216 Japanese quails were distributed randomly in 2 galvanized wire cages, with 3 partitions each and 27 birds/cage. The experimental design consisted of randomized blocks with 2 treatments (air velocity at the feeder: 0, 1, 2, and 3 m/s and air temperature: 17, 23, 29, and 35°C) and 6 replicates. The productive performance was analyzed statistically (Sigma Plot 12.0) by 2-way ANOVA, with treatment means separated by the Tukey test (P < 0.05). To evaluate the main effects and interactions of the factors, the Holm-Sidak multiple comparisons test was performed using a mild condition as the control group (0 m/s). Feed intake did not differ (P > 0.05) among birds reared at temperatures of 23, 29, and 35°C, but higher feed intake was noted at 17°C. The mean values of egg production increased significantly (P < 0.05) with increased air velocity levels. It was observed that there was an increase in egg production and feed intake with the intensification of air velocity at the feeder, regardless of ambient temperature. Egg weight and feed conversion were not affected by air velocity treatments (P > 0.05). There was a significant positive correlation between air temperature and mean surface temperature and head surface temperature. In contrast, a significant negative correlation was observed between air velocity and mean surface temperature and head surface temperature. Productive performance was affected by temperature and air velocity, except for egg weight and feed conversion, which was not influenced by air velocity. Air velocity is important in removing heat from the surface of birds.

Transactions of the ASAE, 1988

ABSTRACT Amodel for predicting layer performance as a function of inside temperature was used to ... more ABSTRACT Amodel for predicting layer performance as a function of inside temperature was used to determine the effects of evaporative cooling and local climatic effects on economic return. A stochastic weather model analysis was used to determine the effects of geographic location upon production with and without evaporative cooling and the effect of flock placement date. The stochastic analysis demonstrated the need to use a minimum of 50 years of replication to reasonably determine expected performance due to significant yearly variations in production response. Yearly variations were particularly large for the number of eggs produced and their distribution by size. The stochastic analysis yielded very different results than an analysis using a deterministic weather model, which has been the normal method of analysis to date. The simulation results strongly indicated that evaporative cooling can provide significant production benefits even in moderate northern climates and that flock placement date strongly affected expected returns.

Poultry Science, 2019

We examined the effects of water-chilled perches as cooling devices on hen performance during 2 s... more We examined the effects of water-chilled perches as cooling devices on hen performance during 2 summers using daily cyclic heat. White Leghorns, 17 wk of age, were assigned to 36 cages arranged into 6 banks. The banks were assigned to cooled perches, air perches, and no perches resulting in 2 replicate banks and 12 cages per treatment. Chilled water (10 • C) was circulated through the cooled perches during heat episodes. Daily cyclic heat of 35 • C was applied from 0600 to1800 h with a lowering of temperature to 28 • C from 1800 to 0600 h during the 2014 and 2015 summers when hens were 21 to 35 and 73 to 80 wk of age, respectively. Mortality and egg production were recorded daily. Feed utilization, egg weight, and shell quality traits were measured at 4-wk intervals during the heat episodes and at 8-wk intervals during thermoneutrality. Body weight was determined at 17, 35, 72, and 80 wk of age and physical condition at 80 wk of age. At several ages during the heat episodes, cooled perch hens had increased egg production (P < 0.0001) and feed usage (P < 0.04) as compared to both air perch and control hens. The cooled perch hens had higher BW at 35 and 72 wk of age (P treatment * age = 0.03) and lower cumulative mortality (P = 0.02) than control hens but not air perch hens. Eggs from cooled perch hens had overall heavier weights (P < 0.0001) and higher breaking force (P < 0.0001) than eggs from the other two group hens. Greater eggshell percentage (P treatment * age = 0.03) and eggshell thickness (P treatment * age = 0.01) occurred at some ages during the 2 heat episodes as compared to the other 2 treatments. Nail length, feet hyperkeratosis, and overall feather score were similar among treatments. These results indicate that cooled perch ameliorates the negative effects of heat stress on egg traits and performance without influencing the physical condition of hens.

Transactions of the ASAE, 1996

A state-space averaging method was employed in the design of a switching control system for a con... more A state-space averaging method was employed in the design of a switching control system for a conventional single-phase, two-speed ventilation fan with time-averaged temperature feedback. The unique state-space averaging method allows the switched, i.e., discontinuous, system to be approximated as a continuous system; thus direct digital control design techniques can be applied for designing the switching controller. Dynamic simulation of the controller action and greenhouse air temperature indicated that the root-mean-square temperature could closely match the set point temperature, and that the switching period affected fluctuations about the set point. The validity of the designed switching controller was confirmed through field tests and compared to a conventional staging control strategy in research greenhouses. The proposed design method shows promise as an alternative to conventional PID systems and stage controllers, and is applicable to any discontinuous switched system. Detailed design development is provided.

Transactions of the ASABE, 2012

Livestock Environment VII, 18-20 May 2005, Beijing, China

Applied Engineering in Agriculture, 2003

Applied Engineering in Agriculture, 2006

Right click to open a feedback form in a new tab to let us know how this document benefits you.

Poultry Science, 2019

Revista Brasileira de Engenharia de Biossistemas, 2020

Transactions of the ASAE, 1998

Transactions of the ASABE, 2011

Poultry Science, 2018

Poultry Science, 2019

Transactions of the ASAE, 1988

Poultry Science, 2019

Transactions of the ASAE, 1996

The objective of this study was to evaluate the bacterial community composition in manure collect... more The objective of this study was to evaluate the bacterial community composition in manure collected from finishing swine in two controlled feeding trials with varying protein and carbohydrate sources and to assess the potential to produce foam. The protein source study included four diets that utilized different combinations of: soybean meal, canola meal, corn gluten meal, and poultry meal; and the carbohydrate source study included six diets with different combinations of: soybean meal, pearled barley, beet pulp, dried distillers grains with solubles (DDGS), soybean hulls and wheat bran. DNA was isolated from manure samples and Automated Ribosomal Intergenic Spacer Analysis (ARISA) was used to profile bacterial community composition. Manure physical properties related to foaming including: methane production rate (MPR, L CH4/g VS day); foaming capacity index (FCI), foam stability (FS, min. Protein and carbohydrate sources tend to impact microbial community composition more than the amount used. Increased methane production rate is somewhat correlated to increased inclusion of corn gluten meal and soybean hulls. Foaming capacity and foaming stability were not strongly correlated to any particular ration or source used.

Heat stress in egg production facilities, especially in caging systems, is an ongoing problem for... more Heat stress in egg production facilities, especially in caging systems, is an ongoing problem for the egg industry, and affects the vast majority of laying hens in the United States. To address this challenge, alternative cooling approaches, including direct wetting of bird surface and cooled perch systems have been developed to provide positive welfare aspect to the laying hens during heat stress events. An experiment in which laying hens were subjected to chronic heat stress was conducted during summer 2014, and is being continued for summer 2015. A caging system with perches in which chilled water is circulated (cooled perch, CP) was equipped with environmental monitoring and thermostatic controls to assess the efficacy of heat stress alleviation, compared to a perch without chilled water (air perch, AP) and a statistical control (CTRL) without any perch. A wireless system for monitoring cage air temperature and relative humidity, water temperature of the perches containing chilled water, and air temperature of AP perches was developed to assess the thermal environment inside the cages. An assessment of the CP system thermal performance, including estimates for heat gains due to convection, conduction from bird, and radiation from surrounding surfaces was done. A database was developed to assist data storage and analysis. Results showed that the CP system performed favorably for the hens. The chiller capacity utilized was marginally capable of maintaining designed cold water temperatures during the heat stress events. A 3.1 to 4.2 kW total heat gain of the cooled perch system with birds perched was observed, with 72, 28 and <1 % from convection, radiation and conduction, respectively. At full chronic heat stress, with all birds on a perch, it is expected that much of the perch heat gain will come from room convective and radiative loading on the perch, rather than from birds.

Atmospheric Environment, 2007

Transactions of the ASABE, 2009

Ventilation rate (VR) is one of the two key elements for quantifying aerial emissions from animal... more Ventilation rate (VR) is one of the two key elements for quantifying aerial emissions from animal production facilities. Direct, continuous measurement of building VR can be challenging and impractical under certain circumstances, e.g., naturally ventilated animal housing or a large number of ventilation fans in the building. This study examined the suitability of estimating VR of broiler houses with built-up litter (mixture of manure and bedding), when supplemental heating was not in use, through either carbon dioxide (CO 2) balance or the relationship of VR to CO 2 concentration difference between exhaust and inlet air. The reference VR was based on direct measurement by continuously monitoring operation of the in-situ calibrated exhaust fans. The comparative analysis of the direct method vs. each indirect method was conducted for a measurement integration time (MIT) of 10, 30, 60, or 120 min. The analyses revealed that MIT of 30 min or greater resulted in non-significant differences in VR between the indirect and direct methods. The broiler building VR (m 3 s-1) may be related to the exhaust-inlet CO 2 concentration difference (? CO 2 , ppm) as VR (± 3.0) = 4456 (± 41) ? CO 2-0.786 (± 0.019) at 30 min MIT. The VR may also be determined by the CO2 balance method (including litter CO2 generation) with a correction factor of 0.97 at MIT of 30 to 120 min. If litter CO2 generation is omitted from the total building CO2 production, the actual VR may be estimated by applying a correction factor of 1.077 to the bird respiration CO2 balance VR.. Hence, the CO2 balance or concentration difference method offers a viable alternative or supplemental check for quantifying building VR under certain conditions where direct, continuous VR measurement is not feasible.

Applied Engineering in Agriculture, 2003

Core body temperature is an important physiological measure of animal thermoregulatory responses ... more Core body temperature is an important physiological measure of animal thermoregulatory responses to environmental stimuli. A new telemetric body temperature measurement system was evaluated by three independent laboratories for its research application in poultry, swine, beef, and dairy cattle. In the case of poultry and swine, the system employs surgeryĈfree temperature sensors that are orally administered to allow short-term monitoring. Computational algorithms were developed and used to filter out spurious data. The results indicate that successful employment of the body-temperature measurement method-telemetric or other measurement systems such as rectal or tympanic method, will depend on the specific application. However, due to the cost of the system, the surgeries involved (in some applications), and the need for filtering of data, careful consideration needs to be given to ensure that telemetry is the ideal method for the experiment protocol.

Applied Engineering in Agriculture, 1989

A stochastic weather model was used in conjunction with a broiler performance model to determine ... more A stochastic weather model was used in conjunction with a broiler performance model to determine the effects of outside temperature upon production with and without evaporative cooling. Stochastic simulations were conducted for 200 years at a series of expected outside temperatures between 21°C (69.8°F) and 30°C (86.0°F). Yearly variations were particularly large for mortality, and this variation had a significant impact on the economic returns realized. The stochastic analysis yielded very different results than an analysis using a deterministic weather model, which has been the normal method of analysis to date. The simulation results indicated that evaporative cooling can provide significant production benefits at 25°C (77°F) or higher expected mean daily temperature. *Average value obtained from 200 years of simulations tStandard deviation of the average value

Computers and Electronics in Agriculture, 2001

Conventional staged ventilation systems are commonly used in agriculture to maintain interior env... more Conventional staged ventilation systems are commonly used in agriculture to maintain interior environments near desired conditions for livestock housing and greenhouses. This paper identifies design parameters for fuzzy-based control of these staged ventilation systems. A simple non-steady state heat balance is used in conjunction with a broiler house simulation model, and coupled with a model for the control system, to simulate control system performance. Difficulties with implementation of conventional staged ventilation control, and the proposed fuzzy inference technique, arise because of the discontinuous nature of these highly non-linear systems. Comparisons between the new fuzzy stage controller and conventional staged control are made. Effects of varying the identified design parameters for the fuzzy stage controller, including different degrees of control precision and energy use, rule base complexity, and the rate of change of house temperature are made. Results indicate that existing staged ventilation control systems which utilize microprocessors could realize significantly enhanced control flexibility by a simple software modification to incorporate the fuzzy staged controller method.

The Journal of Applied Poultry Research, 2014

SUMMARY The purpose of this study was to evaluate feeding 2 levels of spray-dried bovine plasma p... more SUMMARY The purpose of this study was to evaluate feeding 2 levels of spray-dried bovine plasma protein (SDP) on production performance of laying hens subjected to high ambient temperatures. Two groups of 96 Hy-Line W-98 hens (38 wk of age) were housed in each of 2 environmentally controlled chambers. At 40 wk of age, all hens were fed 3 diet treatments consisting of (1) a control diet (0% SDP); (2) the control diet supplemented with 0.75% SDP; and (3) the control diet supplemented with 1.50% SDP. Hens in each chamber (8 cages of 4 hens per cage) were ad libitum fed 1 of each diet for 5 wk. The heat stress (HS) chamber was maintained at 21°C (wk 1), 29°C (wk 2), and 35°C (wk 3 to 5). The thermoneutral chamber was maintained at 21°C during wk 1 to 5. A significant main effect of week was observed for hens maintained in the HS chamber for egg production, egg weight, egg mass, and feed consumption, which resulted in acute heat stress causing a reduction in these parameters. Hens fed the 1.50% SDP diet in the HS chamber produced greater (P < 0.05) egg mass on average than hens fed the control or 0.75% SDP diet (wk 1 to 5). During the second week of acute HS (wk 4), hens fed the control and 1.50% SDP diets had greater (P < 0.05) egg production than those fed the 0.75% SDP diet. During wk 5, hens in the HS chamber that were fed the 1.50% SDP diet produced more (P < 0.05) eggs than those fed the control diet. Therefore, based on the results of this study, acute HS negatively affected short-term production performance. In addition, feeding hens an SDP-supplemented diet may have a slight positive effect on production performance when maintained in acute HS conditions.

Transactions of the ASAE, 1992

Sixteen commercially available electronic environmental controllers were evaluated. The units wer... more Sixteen commercially available electronic environmental controllers were evaluated. The units were classified according to enclosure type, analog versus microprocessor based control, power supply, sensors, alarms, control relays and triac output, interval timers, outside temperature feedback, and retail price. An assessment of these controllers indicated several critical limitations in the application of this technology. The use of integrated controllers for animal production has the potential for substantial improvements in production efficiencies. If the limitations observed in the present controller technology, as represented by this sample, are addressed, industry acceptance of the technology can be accelerated. A uniform standard to address this technology is recommended and specific suggestions are provided for what the standard should address. KEYWORDS.

Poultry Science, 2016

We assessed the effects of chilled water cooling perches on hen performance and physiological and... more We assessed the effects of chilled water cooling perches on hen performance and physiological and behavioral parameters under "natural" high temperatures during the 2013 summer with a 4-hour acute heating episode. White Leghorns at 16 wk of age (N = 162) were randomly assigned to 18 cages (n = 9) arranged into 3 units. Each unit was assigned to one of the 3 treatments through 32 wk of age: 1) cooled perches, 2) air perches, and 3) no perches. Chilled water (10 • C) was circulated through the cooled perches when cage ambient temperature exceeded 25 • C. At the age of 27.6 wk, hens were subjected to a 4-hour acute heating episode of 33.3 • C and plasma corticosterone was determined within 2 hours. Egg production was recorded daily. Feed intake and egg and shell quality were measured at 5-week intervals. Feather condition, foot health, adrenal and liver weights, plasma corticosterone, and heat shock protein 70 mRNA were determined at the end of the study at 32 wk of age. The proportion of hens per cage perching, feeding, drinking, panting, and wing spreading was evaluated over one d every 5 wks and on the d of acute heat stress. There were no treatment effects on the measured physiological and production traits except for nail length. Nails were shorter for cooled perch hens than control (P = 0.002) but not air perch hens. Panting and wing spread were observed only on the day of acute heat stress. The onset of both behaviors was delayed for cooled perch hens, and they perched more than air perch hens following acute heat stress (P = 0.001) and at the age 21.4 wk (P = 0.023). Cooled perch hens drank less than control (P = 0.019) but not air perch hens at the age 21.4 wk. These results indicate that thermally cooled perches reduced thermoregulatory behaviors during acute heat stress, but did not affect their performance and physiological parameters under the ambient temperature imposed during this study.

Poultry Science, 2019

We assessed the effects of water-chilled perches as a cooling device on the physiological paramet... more We assessed the effects of water-chilled perches as a cooling device on the physiological parameters of caged laying hens exposed to 2 cyclic heating episodes. White Leghorns, 17 wk of age, were randomly assigned to 36 cages of 6 banks placed in the same room. Each bank was randomly assigned to 1 of 3 treatments: cooled perch (CP), air perch (AP), and no perch (CTRL) resulting in 2 replicate banks and 12 cages per treatment. Chilled water (10°C) circulated through the CP during heat periods when hens were 21 wk to 35 wk and 73 wk to 80 wk of age, respectively. During the heating episodes, hens were submitted to a daily cyclic temperature regimen of 35°C (0600 h to 1800 h) and 28°C (1800 h to 0600 h). Rectal temperature, packed cell volume, heterophil to lymphocyte (H/L) ratio, and plasma levels of triiodothyronine (T3), thyroxine (T4), interleukin (IL)-6, IL-10, immunoglobulin (Ig) Y, interferon (IFN)-γ, and heat shock protein (HSP) 70 were measured on the last day of the 2 heating episodes. At the end of the first heating episode, CP hens had lower rectal temperature (P = 0.02) than both AP and CTRL hens. The CP hens also had lower HSP 70 (P = 0.04) than CTRL hens but not AP hens. At the end of the second heating episode, the CP hens had lower rectal temperature (P = 0.02) and circulating H/L ratio (P = 0.01) than both AP and CTRL hens. The CP hens also had higher levels of T3 (P = 0.002) and T3/T4 ratio (P = 0.0006) than CTRL hens but not AP hens, with a greater packed cell volume than AP hens (P = 0.02) but not CTRL hens. Cytokines and IgY levels were similar among treatments. These results indicate that CP hens were better able to cope with cyclic heat stress than CTRL and sometimes AP hens as noted by the beneficial effects on rectal temperature, thyroid activity, HSP, and H/L ratio.

Transactions of the ASABE, 2006

Twelve commercial broiler houses in the U.S. were each monitored for at least thirteen 48 h perio... more Twelve commercial broiler houses in the U.S. were each monitored for at least thirteen 48 h periods over the course of one year to obtain ammonia emission data. Paired repetition of houses on four farms represents current construction with variety in litter management (built-up or new litter each flock) and climate conditions (cold or mixed-humid). Ammonia concentration was determined using portable electrochemical sensors incorporating a fresh air purge cycle. Ventilation rate was determined via in-situ measurement of fan capacity, fan on-off times, and house static pressure difference. There were seasonal trends in exhaust ammonia concentration (highest in cold weather) and ventilation rates (highest in warm weather) but not for emission rate. Flocks with at least three monitoring periods (13 of 22 flocks) demonstrated similar emission rates at a given bird age among the four study farms and across the seasons. An analysis of emissions from all houses on the three farms using built-up litter resulted in predicted regression slopes of 0.028, 0.034, and 0.038 g NH3 bird-1 d-1 per day of age; the fourth farm, managed with new litter, had the lowest emission rate at 0.024 g NH3 bird-1 d-1. The intercept of these composite relationships was influenced by litter conditions, with flocks on new litter having essentially no emissions for about six days while built-up litter flocks had emissions starting at flock placement. Data from all four farms and all flocks provided a regression slope of 0.031(±0.001 std error) g NH3 bird-1 d-1 per day of age. Emission rate per animal unit for built-up litter flocks indicated very high emissions for the youngest birds (under 14 days of age), after which time the emissions decreased exponentially and were then relatively steady for the balance of the flock cycle.

Poultry Science, 1998

An experiment was conducted to determine the effect of diets with reduced CP and supplemental ami... more An experiment was conducted to determine the effect of diets with reduced CP and supplemental amino acids on broiler performance, N excretion, litter characteristics, and equilibrium NH 3 gas concentration. Results suggest that reducing CP (and lysine) below 241 g/kg (13.7 g/kg lysine) in the diets fed during the first 3 wk may slightly increase feed:gain and therefore may not be advisable. During the period 22 to 43 d of age there were no significant differences in weight gain and BW at 6 wk of age when reducing CP from 215 g/kg (11.5 g/kg lysine) to 196 g/kg (11.3 g/kg lysine), but feed intake and feed:gain ratio increased. However, reducing CP did cause equilibrium NH 3 gas concentration and litter N to decline by 31 and 16.5%, respectively. Both of these advantages will improve air quality within the housing facility and possibly reduce heating costs during winter associated with higher ventilation rates required to reduce elevated NH 3 gas concentrations.

Poultry Science, 1989

A method for economic optimization of torn turkey production was developed by combining an energe... more A method for economic optimization of torn turkey production was developed by combining an energetic model for production characteristics with a building response model. The objective of economic optimization is to maximize the net return from a growout house. Three sets of simulation experiments were conducted to evaluate the model. These were to determine the effect on production and economic predictions of 1) daily outside temperature, 2) flock starting date, and 3) building overhead costs. Two methods of economic optimization were evaluated: per bird day (PBD) and per unit mass (PUM). The PBD strategy resulted in lower growout temperatures, shorter growout periods, and savings of. 1 to .2 cents/kg when compared with a conventional management strategy. The PUM strategy minimized daily costs to maximize net return, with predicted savings of 1.1 to 1.3 cents/kg-The effect of flock starting date significantly affected growout temperature and indicated the sensitivity of the method to outside temperature. The effect of building overhead was an increased potential for savings at 20 C mean outside temperature using the PBD method, and decreased savings for other temperatures and the PUM method. An example of the adaptability of the model to alternate situations is given.

2006 Portland, Oregon, July 9-12, 2006, 2006

This work aimed to develop a software to dimensioning of a Evaporative Cooling System, considerin... more This work aimed to develop a software to dimensioning of a Evaporative Cooling System, considering the energy exchange inside the facilities, and also seeking to simulate the variations of the temperature, relative humidity, comfort conditions, and others psychometrics variables inside the facility. The program was developed in the programming language Object Pascal, by using Delphi 6.0, to work in Windows® System. As result, the software presents the total number of fans and necessary pad area for the appropriate operation of the system, besides distributing them in the extremities of the facilities. It also supplies a complete energy swinging indoor air. The software came simple and efficient, summarizing in a few windows the necessary data for balance sheet analysis of energy in poultry facilities equipped with the adiabatic cooling system, supplying enough information for the correct dimensioning of the system.

Transactions of the ASAE, 1988

T HE utility of combining a stochastic model for mean daily temperature with a deterministic mode... more T HE utility of combining a stochastic model for mean daily temperature with a deterministic model to predict animal and building performance is presented. A major effect of the stochastic input is to incorporate random fluctuations such as are encountered during actual building operation that result in varying costs and income, hence net return, from the building. A method is presented to quantify the economic risk associated with different control options for different building life spans. A step by step statistical approach for evaluating the economic risk is demonstrated using data from stochastic simulations in the literature.

Transactions of the ASAE, 1995

A system consisting of a commercial environment controller attached to a personal computer progra... more A system consisting of a commercial environment controller attached to a personal computer programmed to execute a dynamic simulation model for broiler house thermal response was designed. The building model updates interior environment from solution of first order heat and moisture balances. Feedback of predicted interior temperature is provided to the controller; heating and ventilation equipment assigned in the model affect heat and moisture balances and hence the system response. An object oriented design approach was utilized and described. Governing equations for the building and controller temperature circuit dynamic response were solved in real time with a series of simulations to assess the response of the interior environment to different controller settings. Assessments of controller stage differential, building minimum ventilation rate and system sampling time are provided for a simulated broiler house. The combination of an environment controller and a building thermal model such as that presented here can be used to evaluate environment controllers and building heating and ventilating design, as well as for training purposes.

Transactions of the ASAE, 2000

In this article the growth curves of individual animals for various species were examined to dete... more In this article the growth curves of individual animals for various species were examined to determine the relationship between birth weight and mature size. For the genotypes studied, the birth weight fraction of maturity (F b) was found to range from approximately 0.6% to approximately 10% of mature size. Generally, for most species in this study it was found that F b increased as birth weight became larger and the female of the species generally demonstrated a larger fraction of maturity at birth than did the male animals of the same breed. An equation was developed to predict F b for each genotype with varying degrees of success. Using the developed equation and the birth weight of an individual animal, a physiologically based estimate of the animal's mature size can be obtained.

J Applied Poultry Res, 2023

In August 2021, the U.S. Environmental Protection Agency (EPA) released draft models to estimate ... more In August 2021, the U.S. Environmental Protection Agency (EPA) released draft models to estimate daily NH 3 , H 2 S, PM 2.5 , PM 10 , and total suspended particulates emissions from U.S. broiler operations using inputs of daily mean ambient temperature, relative humidity, and live animal weight. The EPA developed these models using datasets collected between 2005 and 2007. It is important to note that over 15 yr have passed since the original data

Journal of the ASABE, 2023

In August 2021, the U.S. Environmental Protection Agency (EPA) released draft models to estimate ... more In August 2021, the U.S. Environmental Protection Agency (EPA) released draft models to estimate daily NH3, H2S, PM10, M2.5, and TSP emissions from egg-layer houses (high-rise and manure-belt) and manure storage using inputs of daily mean ambient temperature, relative humidity (RH), and hen inventory. These models were developed from refined datasets generated by the National Air Emissions Monitoring Study fieldwork completed in 2009. Notably, they do not include data for cage-free housing. Currently, 66% of U.S. laying hens are housed in cages; thus, these models, if adopted, will have a substantial impact on the U.S. egg industry. This study evaluated the EPA draft models’ robustness and assessed model outputs for egg production systems under differing climate scenarios. The EPA draft models distort emission factors for bird inventories to be lower or higher than those used to develop the models. With inventory held constant, the marginal influence of ambient temperature and RH on daily emissions varied substantially, with some values falling below the measurement detection threshold while others exceeding literature findings. For twelve representative U.S. locations representing differing climates, substantial differences in emission factors were found for bird inventories outside the range in the database. Annual emissions estimated from inventories used to develop the EPA models also varied by location. We conclude that the current draft EPA emission models cannot be used to the degree of precision that is suitable to apply to a wide range of layer facilities, particularly cage-free systems. Revisions are suggested to accommodate a greater range of climates, laying hen facility types, and inventories for practical emission estimations."

Sensors, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

The thermal environment affects the behavior of laying and better understanding of the effects of... more The thermal environment affects the behavior of laying and better
understanding of the effects of thermal environment on the behavior of
laying can allow the inference of the welfare of the birds. As the need to
better understand the behavioral responses of quail to the environment
especially in the initial phase posture become necessary new studies
related to the ambience. Therefore, the aim of this study was to evaluate
the effect of different levels of air speeds in the behavior of Japanese
quail in the initial phase posture submitted to thermoneutral temperature
in climatic chambers. Were used 216 Japanese quails maintained in 4
climatic chambers at thermoneutral temperature (23°C) and relative
humidity of 50 to 70%, where they were housed and distributed randomly
into 2 galvanized wire cages. Each cage had 3 partition in which
they were housed 27 birds/cage, 9 birds/distribution giving a density of
approximately 155.6 cm2/bird. The ventilation system was distributed
in each climatic chamber at thermoneutral temperature setting 4 treatments
with average values of air flow, air 1.0 m/s: (chamber 1); 2.0 m/s:
(chamber 2); 3.0 m/s: (chamber 3); 0.0 m / s (chamber 4 - Control).
The behavioral assessment was performed using a ethogram with the
following behaviors: Eating; Drink; Stop; Active and Others. The evaluation
of the behavior was carried in 30 min intervals during the morning
and in the afternoon. The behavior data were statistically analyzed by
ANOVA and then the significant treatments were submitted to Tukey
test (P < 0.05). It was observed that the results indicate that the air speed
levels did not affect (P < 0.05) the behavior of birds for thermoneutrality
23°C (thermal comfort) for the morning. In the afternoon there was
a significant difference (P < 0.05) between the air velocity levels 0.0
and 1.0 m/s just to behavior stop, and these air velocity levels equal to
others. It is concluded that the airspeed does not interfered in behavior
in the morning but influenced in the afternoon.

2003, Las Vegas, NV July 27-30, 2003, 2003

2004, Ottawa, Canada August 1 - 4, 2004, 2004

The beef industry is an important component of Kentucky’s agriculture accounting for approximatel... more The beef industry is an important component of Kentucky’s agriculture accounting for approximately 15% of the state’s agricultural sales in 2000. Dairy also plays a prominent role in Kentucky’s agriculture (state rank of 18th). The state’s significant cattle production occurs primarily on small to mid-sized farms averaging between 25 and 40 head of cattle per operation. Considering this upward trend in cattle production along with Kentucky’s 140,000 km of rivers and streams, rolling pastures and karst geology, the potential for damage to riparian ecosystems from uncontrolled livestock access is high. The objective of this project was to determine the influence of alternate management strategies such as off-stream water, fencing, shade (permanent and movable), and pasture improvements on cattle behavior in grazed pastures of the humid region of the U.S. The project site, located on the University of Kentucky’s Animal Research Center, consisted of two replications of three treatments: control, selected BMPs with free access to the stream, and selected BMPs with limited access to the stream. Cattle placed on the research pastures were fitted with GPS collars to track their positions. The use of GPS collars for tracking animal movements and behaviors eliminates errors often introduced in human observations. GPS collar data was collected at five minute intervals for seven sampling events over a two year period. Results indicated that the BMP systems (i.e. treatments) did not affect cattle position preference, and as such, these BMP systems did not decrease the amount of time cattle spent along the streambanks. However, significant time effects were noted the cooling pasture feature trees as cattle sought relief from the heat and humidity. Increased cattle presence along the streambank during the daytime period was linked to longer day light hours, but the impractical nature of the model indicated that additional independent variables were required. For the nighttime data set, the significant seasonal variable was solar radiation, as decreases in solar radiation resulted in the model predicting that cattle would tend to avoid the pasture feature trees. The majority of non-zero solar radiation values, while relatively small in comparison to the daytime values, were in the periods dividing daytime and nighttime (i.e. dawn and dusk). Thus, the primary driving factor with regards to cattle position preference appeared to be a desire to avoid trees, a pasture feature often associated with loafing, possibly in favor of grazing. While the results of this study indicated that no significant treatment effects were present, the significant time effects suggest that the strategic development of 1) cooling features such as shade, wading ponds or water misters and 2) areas of high forage quality and quantity may influence cattle position preference.