Field Implementation of Precision Livestock Farming: Selected Proceedings from the 2nd U.S. Precision Livestock Farming Conference.

Precision Livestock Farming (PLF) involves the real-time monitoring of images, sounds, and other biological, physiological, and environmental parameters to assess and improve animal health and welfare within intensive and extensive production systems [...].

Impacts of Air Velocity Treatments under Summer Conditions: Part II-Heavy Broiler's Behavioral Response.

Broiler chickens exposed to heat stress adapt to various behavioral changes to regulate their comfortable body temperature, which is critical to ensure their performance and welfare. Hence, assessing various behavioral responses in birds when they are subjected to environmental changes can be essential for assessing their welfare under heat-stressed conditions. This study aimed to evaluate the effect of two air velocity (AV) treatments on heavy broilers' behavioral changes from 43 to 54 days under summer conditions. Two AV treatments (high and low) were applied in six poultry growth chambers with three chambers per treatment and 44 COBB broilers per chamber from 28 to 61 days in the summer of 2019. Three video cameras placed inside each chamber (2.44 m × 2.44 m × 2.44 m in dimension) were used to record the behavior of different undisturbed birds, such as feeding, drinking, resting, standing, walking, panting, etc. The results indicate that the number of chickens feeding, drinking, standing, walking, sitting, wing flapping, and leg stretching changed under AV treatments. High AV increased the number of chickens feeding, standing, and walking. Moreover, a two-way interaction with age and the time of day can affect drinking and panting. This study provides insights into heavy broilers' behavioral changes under heat-stressed conditions and AV treatments, which will help guide management practices to improve birds' performance and welfare under commercial conditions in the future.

Impacts of Air Velocity Treatments under Summer Condition: Part I-Heavy Broiler's Surface Temperature Response.

Heavy broilers exposed to hot summer conditions experience fluctuations in surface temperatures due to heat stress, which leads to decreased performance. Maintaining a bird's homeostasis depends on several environmental factors (temperature, relative humidity, and air velocity). It is important to understand the responses of birds to environmental factors and the amount of heat loss to the surrounding environment to create thermal comfort for the heavy broilers for improved performances and welfare. This study investigates the variation in surface temperatures of heavy broilers under high and low air velocity treatments. Daytime, age and bird location's effect on the surface temperature variation was also examined. The experiment was carried out in the poultry engineering laboratory of North Carolina State University during summers of 2017, 2018, and 2019 as a part of a comprehensive study on the effectiveness of wind chill application to mitigate heat stress on heavy broilers. This live broiler heat stress experiment was conducted under two dynamic air velocity treatments (high and low) with three chambers per treatment and 44 birds per chamber. Surface temperatures of the birds were recorded periodically through the experimental treatment cycles (flocks, 35-61 d) with infrared thermography in the morning, noon, evening, and nighttime. The overall mean surface temperature of the broilers under two treatments was found to be 35.89 ± 2.37 °C. The variation in surface temperature happened due to air temperature, thermal index, air velocity, bird's age, daytime, and position of birds inside the experimental chambers. The surface temperatures were found lower under high air velocity treatment and higher under low air velocity treatment. During the afternoon time, the broilers' surface temperatures were higher than other times of the day. It was also found that the birds' surface temperature increased with age and temperature humidity indices. Based upon the experimental data of five flocks, a simple linear regression model was developed to predict surface temperature from the birds' age, thermal indices, and air velocity. It will help assess heavy broilers' thermal comfort under heat stress, which is essential to provide a comfortable environment for them.

Size-segregated physicochemical properties of inhalable particulate matter in a tunnel-ventilated layer house in China.

This study investigated the physicochemical properties of the particles in a typical commercial laying hen barn in Southeast China. Mass concentrations and size distributions of the particulate matter (PM) and the key components (incl. organic carbon (OC), element carbon (EC), and the water-soluble inorganic ions (WSIIs)) were analyzed. The result shows that the mass concentrations of PM accumulated along with the airflow inside the house, with the total mass of the sampling particles increasing from 843.66 ± 160.74 µg/m3 at the center of the house to 1264.93 ± 285.70 µg/m3 at the place close to exhaust fans. The particles with the aerodynamic equivalent diameter, Dp > 9 µm, coarse particles (2.1 µm < Dp ≤ 9 µm), fine particles (Dp ≤ 2.1 µm) accounted for around 50%, 40%, and 10% of the total mass of the sampling particles, respectively. Mass closure analysis shows secondary inorganic ions (NH4+, SO42- and NO3-) were abundant in the fine-mode fraction and OC accounted for more than 40% of the coarse particles. Size distribution analysis shows that the three secondary inorganic ions were bimodally distributed, and the rest tested components were unimodally distributed. The ratios of OC/EC in fine particles were smaller than those in the coarse particles. The equivalent concentration of WSIIs indicated that fine particles were slightly acidic, and the large size particles were slightly alkaline. Knowledge gained from this study will lead to a better understanding of physicochemical properties, sources, and formation of PM.

Effect of dietary coarse corn inclusion on broiler live performance, litter characteristics, and ammonia emission.

Ammonia (NH3) emission from nondigested nutrients in poultry creates additional adverse environmental impacts on soil, water, air, and health. Mitigating NH3 emission has become vital for the poultry industry to remain sustainable. As the presence of large particles in the feed stimulates the broiler gizzard to retain ingesta in the gastrointestinal tract longer and improve digestive efficiency, the inclusion of large particles in feed may lead to less nitrogen (N) and moisture content (MC) in feces such that lower NH3 production would be expected. This chamber study investigated the effects of dietary coarse corn (CC) inclusion on broiler live performance, litter characteristics, and NH3 emission. One hundred eighty female broilers (Ross 344 × 708 strains) at day 21 were randomly placed in 6 chambers with 2 dietary treatments (0% CC and 50% CC), with 3 chambers per treatment and 30 birds per chamber for 3 wks. The results showed that the 50% CC inclusion (1) decreased broiler feed intake and BW without affecting mortality-adjusted feed conversion ratio from day 21 to 42; (2) increased gizzard weight and decreased proventriculus weight; (3) decreased N content and MC in litter; and (4) decreased NH3 concentrations in the chambers, as well as NH3 emission from the chambers. Dietary CC inclusion could be an effective way to mitigate broiler litter N content and MC as well as NH3 emission.

Spatial and temporal variations of PM2.5 mass closure and inorganic PM2.5 in the Southeastern U.S.

Fine particulate matter (i.e., PM2.5) has gained extensive attention owing to its adverse effects. The impacts of PM2.5 may vary in time and space due to the spatiotemporal variations of PM2.5 number size distribution and chemical compositions. This research analyzed the latest PM2.5 chemical compositions measurements with an aim to better understand the dynamic changes of PM2.5 in response to emission reductions due to the new regulations. The particulate measurements from the Southeastern Aerosol Research and Characterization (SEARCH) network between 2001 and 2016 were analyzed for the spatiotemporal variations of PM2.5 and inorganic PM2.5 (iPM2.5 = SO42- + NH4+ + NO3-) chemical compositions in the Southeastern United States (U.S.). It was discovered that PM2.5 and iPM2.5 mass concentrations exhibited significant downward trends in 2001-2016. Both PM2.5 and iPM2.5 mass concentrations were higher at urban and inland sites than rural/suburban and coastal sites. The higher iPM2.5 concentrations at agricultural sites were attributed to the influences of ammonia (NH3) emissions from animal feeding operations (AFOs). The iPM2.5 was the dominant contributor to PM2.5 in 2001-2016 at the coastal sites, whereas organic carbon matter (OCM) was the major contributor to PM2.5 after 2011 at the inland sites. Our data analysis suggests that significant decrease of PM2.5 concentrations is attributed to the reductions in nitrogen oxides (NOx) and sulfur dioxide (SO2) emissions in 2001-2016. Findings from this research provide insights into the development of effective PM2.5 control strategies and assessment of air pollutants exposure.

Major ionic compositions of fine particulate matter in an animal feeding operation facility and its vicinity.

Animal feeding operations (AFOs) produce particulate matter (PM) and gaseous pollutants. Investigation of the chemical composition of PM2.5 inside and in the local vicinity of AFOs can help to understand the impact of the AFO emissions on ambient secondary PM formation. This study was conducted on a commercial egg production farm in North Carolina. Samples of PM2.5 were collected from five stations, with one located in an egg production house and the otherfour located in the vicinity ofthe farm alongfour wind directions. The major ions of NH4+, Na+, K+, SO4(2-), Cl-, and NO3- were analyzed using ion chromatography (IC). In the house, the mostly abundant ions were SO4(2-), Cl-, and K+. At ambient stations, SO4(2-), and NH4+ were the two most abundant ions. In the house, NH4+, SO4(2-), and NO3- accounted for only 10% of the PM2.5 mass; at ambient locations, NH4+, SO4(2-), and NO3- accounted for 36-41% of the PM2.5 mass. In the house, NH4+ had small seasonal variations indicating that gas- phase NH3. was not the only major force driving its gas-particle partitioning. At the ambient stations, NH4+ had the highest concentrations in summer In the house, K+, Na+, and Cl- were highly correlated with each other In ambient locations, SO4(2-) and NH4+ had a strong correlation, whereas in the house, SO4(2-) and NH4+ had a very weak correlation. Ambient temperature and solar radiation were positively correlated with NH4+ and SO4(2-). This study suggests that secondary PM formation inside the animal house was not an important source of PM2.5. In the vicinity, NH3 emissions had greater impact on PM2.5 formation.

Ammonia concentrations and modeling of inorganic particulate matter in the vicinity of an egg production facility in Southeastern USA.

Ammonia (NH3) is an important base gas and can react with acidic species to form atmospheric aerosols. Due to the rapid growth of poultry and swine production in the North Carolina Coastal Plain, atmospheric NH3 concentrations across the region have subsequently increased. Ammonia concentrations and inorganic particulate matter (PM) at four ambient stations in the vicinity of an egg production facility were measured for 1 year using PM2.5 speciation samplers with honeycomb denuders and ion chromatography (IC). Meanwhile, concentrations of NH3 and inorganic PM in one of the egg production houses were also simultaneously measured using a gas analyzer for NH3 and the filter pack plus IC method for inorganic PM. An equilibrium model-ISORROPIA II was applied to predict the behavior of inorganic aerosols in response to precursor gas concentrations and environmental parameters. Average ambient NH3 concentrations varied from 10.0 to 27.0 µg/m(3), and they were negatively correlated with the distances from the ambient location to the nearest egg production house exhausts. Ambient NH3 concentrations were higher in warm seasons than in cold seasons. Measured NH3 concentrations agreed well with ISORROPIA II model predictions at all sampling stations. For the ambient stations, there was a good agreement in particle phase NH4 (+) between the model simulation and observations. For the in-house station, the model simulation was applied to correct the overestimation of particle phase NH4 (+) due to gas phase NH3 breaking through the denuders. Changes in SO4 (2-), NO3 (-), and Cl(-) yield proportional changes in inorganic PM mass. Due to the abundance of NH3 gas in the vicinity area of the monitored farm, changes in NH3 concentrations had a small effect on inorganic PM mass. Aerosol equilibrium modeling may be used to assess the influence of precursor gas concentrations on inorganic PM formation when the measurements for some species are unavailable.

Identification of Bioaerosols Released from an Egg Production Facility in the Southeast United States.

This field study investigated biological characteristics of aerosols emitted from a commercial egg production farm (layer operation). Bioaerosol samples were taken on this farm at five sampling locations covering emission source (inside a layer barn) and four ambient surrounding stations at four wind directions. All-glass impingers (AGI) were used for the field sampling. AGI fluid samples were plated in duplicate on Trypticase Soy Agar for growth of bacteria and Sabouraud Dextrose Agar for growth of fungi. The most prominent bacterial colony types were identified using a combination of methods that include recording characteristics of colony morphology; performing a Gram staining method and metabolic analyses using the Biolog system. Results from thirty-five AGI samples taken at the five stations through seven sampling events over four seasons indicate that there were significantly lower total bacterial concentrations in the samples collected from ambient stations as compared with the samples collected in the layer house; the mean bacterial concentration at the in-house sampling station was 3.86×10(5)±1.74×10(5) cfu/m(3), whereas the mean bacterial concentrations at four ambient stations in the vicinity of the farm ranged from 1.3×10(3) to 6.2×10(3) cfu/m(3) with no significant differences in mean among ambient stations. There were also no significant differences in fungi concentrations among all sampling stations. Mean fungi concentrations at the in-house station was 3.0×10(3)±4.45×10(3) cfu/m(3), whereas the mean concentrations at the ambient stations ranged from 7.4×10(3) to 1.7×10(4) cfu/m(3). The most prominent bacterial species differed among all five stations. Three of the most prominent bacteria from samples taken at all five stations were gram positive. Fungal type also differed from station to station.

Field evaluation of particulate matter measurements using tapered element oscillating microbalance in a layer house.

The tapered element oscillating microbalance (TEOM) is one type of continuous ambient particulate matter (PM) monitor. Adsorption and desorption of moisture and semivolatile species may cause positive or negative artifacts in TEOM PM mass measurement. The objective of this field study was to investigate possible uncertainties associated with TEOM measurements in the poultry operation environment. For comparisons of TEOM with filter-based gravimetric method, four instruments (TEOM-PM10, low-volume PM10 sampler TEOM-PM2.5, and PM2.5 speciation sampler) were collocated and tested inside a poultry house for PM2.5 and PM10 (PM with aerodynamic equivalent diameter < or =2.5 and < or =10 microm, respectively) measurements. Fifteen sets of 24-hr PM10 concentrations and 13 sets of 24-hr PM2.5 measurements were obtained. Results indicate that compared with filter-based gravimetric method, TEOM gave significantly lower values of both PM10 and PM2.5 mass concentrations. For PM10, the average ratio of TEOM to the gravimetric method was 0.936. For PM2.5, the average ratio of TEOM to the gravimetric method was 0.738. Particulate matter in the poultry houses possibly contains semivolatile compounds and moisture due to high levels of relative humidity (RH) and gas pollutants. The internal heating mechanism of the TEOM may cause losses in mass through volatilization. To investigate the effects of TEOM settings on concentration measurements, the heaters of two identical TEOMs were set at 50 degrees C, 30 degrees C, or no heating at all. They were collocated and tested for total suspended particle (TSP), PM10, and PM25 measurements in layer house for 6 weeks. For all TSR PM10, and PM2.5 measurements, the internal TEOM temperature setting had a significant effect (P < 0.05). Significantly higher PM mass concentrations were measured at lower temperature settings. The effects of environmental (i.e., temperature, RH, NH3 and CO2 concentrations) and instrumental (i.e., filter loading and noise) parameters on PM measurements were also assessed using regression analysis.