Hongwei Xin

Partial surface wetting to cool caged laying hens (Hy–Line W–98 breed, 34 µ1 wk) was investigated for a range of acute heat challenge conditions. The cooling water required to prevent surface and core body temperatures of the hen from escalating was expressed in terms of water spray interval (SI 10 , min) at a constant spray dosage (10 mL hen –1) and evaporation rate (ER, mL min –1) of the sprayed water. The thermal conditions used in this study consisted of air velocity (V) of 0.2 to 1.2 m s –1 in combination with air vapor pressure deficit (VPD air) of 2.1 to 5.3 kPa that corresponds to dry–bulb temperature (t db) of 35³C to 41³C and dew–point temperature (t dp) of 21³C to 27³C. ER was directly proportional to VPD air · V. The empirical relationships provide a basis for optimizing operation of partial surface wetting systems to relieve caged layers of heat stress in commercial production settings. dult laying hens have a thermoneutral zone (TNZ) of 21³C to 25³C. Deviation of the thermal environment from TNZ leads to performance reduction or mortality under severe conditions. A number of studies have shown the adverse effects of elevated environmental temperature on laying hen performance

SUMMARY We present a measurement method for NH3 emissions from mechanically ventilated poultry buildings, which has been successfully used in a multistate, multidisciplinary research project to establish baseline values for the United States. To accurately determine building emission rate (ER, the product of pollutant concentration and exhaust airflow rate), accurate measurements must be made over representative periods and production phases.

Summary A multi-state, multi-disciplinary project is developing a comprehensive database of ammonia (NH3) emission rates (ER) from US poultry facilities. The influence of common management strategies and practical means of reducing NH3 emissions are under study. The measurement of ER during winter and spring from 4 broiler houses with re-used ('built-up') litter is described in this paper. Ammonia concentrations were

Direct measurement of building ventilation rate in livestock housing is a formidable task due to uncontrollable variations in fan and system performance that are caused by factors such as building static pressure, fan belt slippage, and dust accumulation on shutters and blades. Estimating building ventilation rate by an indirect method based on a CO2 balance offers a potentially viable alternative

ABSTRACT Twelve commercial broiler houses in the United States were each monitored for thirteen 48-hour periods over the course of one year to obtain ammonia emission data. Houses on four farms in two states included paired repetition of houses chosen to represent the variety in modern construction, litter management practices, and climate conditions. Ammonia concentration was determined by portable monitoring units incorporating electrochemical sensors with a fresh air purge cycle. Ventilation rate was determined via in-situ measurement of fan capacity versus static pressure difference of all fans in each house using an anemometer array. During each study period, fan on-off times and house static pressure difference were monitored. There were seasonal trends in house ammonia concentration and ventilation rates but offsetting relationships between these two factors resulted in fairly uniform ammonia emission rates from flocks over the seasons. Emission rates were highest during periods of warmest weather, especially with larger birds. The best predictive relationship for emission rate was found between average daily emission rate per bird and flock age. Emission rate per floor area versus flock age acknowledges the ammonia emission surface area, and offered another good predictive relationship. Emission rate in terms of animal unit (500 kg) for built-up litter flocks indicated very high emissions per AU for the youngest birds (under about 10 days of age), after which time the emissions were relatively steady for the balance of the flock cycle. Flocks that had at least three monitoring periods (13 of 22 flocks studied) provided emission rates that were very similar among the four study farms and across the seasons (regression slope average 0.031 g NH3 bird-1 d-1 per day of age; std. dev. 0.0057). When all flock data from each farm was analyzed as a composite, for the three farms with built-up litter the predicted regression slopes were 0.028, 0.034 and 0.037 g NH3 bird-1 d-1 per day of flock age; the fourth farm had new litter for each flock resulting in the lowest emission rate of the study farms at 0.024 g NH3 bird-1 d-1 per day of flock age. The intercept of these composite linear relationships was influenced by litter conditions with flocks on new litter having essentially no emissions for about 6 days while built-up litter flocks had an intercept near 0.

A multi-state, multi-disciplinary project is developing a comprehensive database of ammonia (NH3) emission rates (ER) from US poultry facilities. The influence of common management strategies and practical means of reducing NH3 emissions are under study. The ...

... An Evaluation of Pullet and Young Laying Hen Ammonia Aversion Using a Preference Test Chamber Morgan Hayes Hongwei Xin Hong Li ... Research has shown that concentrations of 25 ppm or greater are aversive to hens (Kristensen et al., 2000; Jones et al., 2005). ...

ABSTRACT Heat and moisture production (HMP) values are used to size ventilation fans in animal housing. The HMP values that are currently published in the ASABE standards were from data published in 1975. This study is one of a series of studies being conducted to update the HMP values for the ASABE and ASHRAE (American Society of Heating Refrigeration, and Air Conditioning Engineers) Standards. This study focused on the HMP measurements on nursery and growing pigs in the weight range of 8 to 44 kg. Ninety-six nursery pigs were randomly assigned to one of 24 pens (4 pigs /pen) and subjected to one of four temperatures between 25 and 35°C. Forty-eight growing pigs were penned in groups of 2 and subjected to one of four temperatures between 18 and 33°C. Heat production rate (HP) was determined using indirect calorimetry methods, after the animals were acclimated for a minimum of 1 week to a particular temperature. Each measurement was made on a pen of animals (either 2 or 4 pigs/pen) over a 21-hr period. It was determined that HP decreased and moisture production (MP) increased as environmental temperature increased. In the nursery age piglets, the level of feed consumption had a greater impact on HP than temperature. Dynamic measurements showed a diurnal HP pattern; HP was higher during light period than during dark period, with an immediate increase as the lights were turned on.

ABSTRACT Recently, there has been much interest in and movement toward alternative housing systems for laying hens. Associated with the movement are many questions to be addressed concerning sustainability of such systems. This study quantifies electricity and propane usage in two side-by-side aviary hen houses each holding 50,000 laying hens, located in Iowa, USA. Electricity usage was also partitioned into different housing components, including ventilation, lighting, and manure-drying. Electricity for ventilation is most variable in that it was the largest of all the components with 60% of the total electric energy in summer but only approximately 5% in winter. The mechanical ventilation efficiency was approximately 25.5 m3/(hr-Watt) (15 CFM per Watt) at static pressure of 12.5 Pa (0.05 inch water column). The continuously running manure-drying blowers accounted for the largest proportion of electricity use in winter with approximately 350 kWh daily consumption. Over the 15-month monitoring period, both houses had an average electricity cost of 3.6 cents per kg of egg produced (based on the rate of $0.09/kWh). The fuel usage was minimal (less than 425 liters of propane in one year), although the winter weather during the monitoring period was milder than the historical climatic conditions.

ABSTRACT There has been an increased interest in alternative housing for laying hens in certain parts of the world, including the United States. Associated with the movement are many questions to be addressed concerning sustainability of such systems. This study continually quantifies concentrations and emissions of ammonia (NH3), carbon dioxide (CO2), methane (CH4), and particulate matters (PM10 and PM2.5) for two side-by-side aviary barns each housing 50,000 Hy-Line brown laying hens, located in the Midwestern US. The gaseous concentrations were continually monitored using a photoacoustic multi-gas analyzer, while the PM concentrations were measured with tapered element oscillating microbalances (TEOMs). Barn ventilation rate was determined through monitoring the operation time of ventilation fans that had been calibrated in-situ. Nineteen consecutive months of monitored data (June 2010 – Dec 2011) are analyzed and presented. Daily indoor NH3, CO2, CH4, PM10, and PM2.5 concentrations (mean ±SD) were 8.7 (±8.4) ppm, 1,636 (±1,022) ppm, 10.0 (±6.8) ppm, 2.3 (±1.6) mg/m3, and 0.25 (±0.26) mg/m3, respectively. The aerial emissions are expressed as quantities per hen, per animal unit (AU, 500 kg body weight), and per kg of egg output. Daily emission rates were 0.15 (±0.08) NH3, 75 (±15) CO2, 0.09 (±0.08) CH4, 0.11 (±0.04) PM10, and 0.008 (±0.006) PM2.5 g/bird. The results are compared to reported emission values for conventional (high-rise and manure-belt) US laying-hen housing systems. Data from this study provide baseline concentration and emission values from the aviary housing system in the Midwestern US.

ABSTRACT An Excel-based spreadsheet model has been developed to delineate ventilation rate (VR), supplemental heat need (Hs), balance temperature (tbal, outdoor temperature below which Hs is required to maintain the desired indoor temperature), energy use and cost for Hs in alternative (aviary and enriched colony) vs. conventional cage laying-hen houses. The model was applied to the Midwestern U.S. housing characteristics (same land footprint) and winter weather conditions (−30 °C to 5 °C ambient temperature, and a constant relative humidity or RH of 70%). Effects of hen stocking density, target indoor temperature and RH (ti, RHi), building insulation, and light period vs. dark period on VR, tbal and Hs were examined. For the housing characteristics considered and target indoor condition of 25 °C and 60% RH, tbal for the alternative housing systems was found to be 2.0–2.6 °C higher than that for the conventional cage counterpart. The supplemental heater capacity would need to be 20.5–22.0 kW per 10,000 hens for the aviary houses (107,000-hen capacity) and 17.6 kW per 10,000 hens for the enriched colony house (124,000-hen capacity). Annual Hs was estimated to be 0.09 and 0.12 MJ [kg egg]−1 for the enriched and aviary houses, respectively. The corresponding Hs cost (in US dollars) would be, respectively, 0.11 and 0.15 US cent [kg egg]−1 at a wholesale liquid propane (LP) fuel price of $0.32 l−1 ($1.21 gal−1) or 0.26 and 0.35 US cent [kg egg]−1 at a retail LP fuel price of $0.75 l−1 ($2.84 gal−1). Among all the influencing factors considered, ti and RHi setpoints had more pronounced impacts on tbal and Hs. The analysis indicated that Hs energy cost for the alternative housing systems in the Midwestern USA is less than 0.3% of the total production cost. The simulation model was validated with measured heating energy use by a commercial aviary house in northern Iowa and the difference between the predicted and field-measured Hs values was less than 5%. This interactive model can be readily used for analysis of other laying-hen housing, climatic conditions, and/or management scenarios.

STP a I STP NH NH P P T T MV MW C Q ER × × × × = 3 3 (1) ... For the national air emissions study, ammonia ER incorporates periodic background measurement: ... STP a I STP NH background NH NH P P T T MV MW C C Q ER × × × ⎭ ⎬ ⎫ ⎩ ⎨ ⎧ − × = 3 3 3

Abstract. This work evaluates a simple method to measure ammonia concentration average for building emissions measurements, using a low-cost system (Portable Monitoring Unit, PMU). The method is compared to a more sophisticated (Mobile Air Emission Monitoring Unit, ...

Spray-application of membraneless acidic electrolyzed water (MLAEW) is a novel technique for disinfection in livestock houses. This study investigated the loss of free chlorine (FC - the major germicidal component in MLAEW) over distance during spraying, as affected by air temperature and initial FC concentration. The anti-microbial effect of MLAEW on airborne bacteria from an aviary laying-hen house was examined. MLAEW was prepared at two FC concentrations: app. 15 and 60 mg L⁻¹, and sprayed at three air temperatures (18, 25, 32 °C). The original MLAEW solution and MLAEW aerosols collected at 0, 25, and 50 cm from the spray nozzle were analyzed for FC concentrations. Bacteria were immersed into these MLAEW samples and numerated for viable count after 0.5, 2 and 5-min treatments. MLAEW aerosols collected at 0 cm lost 11.7-13.2% FC, compared with the original MLAEW solution. This initial loss was affected neither by the initial FC concentration (P = 0.13) nor by air temperature (P = ...

Standard protocols for sampling and measuring gas, dust and odor emissions from livestock buildings are needed to guide scientists, consultants, and regulators. Recently, two federally funded, multi-state projects have initiated field studies to measure emissions of PM10, ...