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Maintaining proper environment in hen house by mechanical ventilation is essential for the production. In order to fully mix the cold inlet air in winter with room air, the free space beneath ceiling of hen house is normally large. However, in summer, such a design is not optimal for tunnel ventilation that air is drawn into one end of the house and exhausted at the other end, i.e., a large portion of the ventilation air would pass through the free space under ceiling instead of caged-hen occupied zone (CZ), which leads to reduced air speed in CZ as well as wind chill effect. To solve this problem, application of deflectors beneath the ceiling was investigated by computational fluid dynamics (CFD) simulations. To assess the effect of deflectors, the indoor air speed and distribution with deflectors were compared to those without deflectors. The effects of heights (0.4 m, 0.55 m, 0.7 m, 0.85 m and 1 m) and intervals (6 m, 9 m, 12 m, 15 m and 18 m) of deflectors on air speed and distribution in CZ were analyzed. The CZ was modelled as porous media in simulations to reduce mesh numbers. The resistance coefficients in x, y and z directions were derived by pressure drop through CZ in a virtual wind tunnel with one cage of birds. The hen house model was validated by a set of field measurement data. A reasonable agreement was found between measured and simulated values (the relative difference is within 10%). The investigation showed that the deflectors could significantly direct airflow downwards and increase the air speed in CZ and aisle zone by 0.66 m s −1 and 0.91 m s −1 , respectively, than those without deflectors, when deflectors were 1 m height with interval of 6 m. The average air speed changes in CZ were linearly related to the height and interval of deflectors. Along the length direction of cage, the variation trends of air speed were almost identical under different heights of deflectors, while under varied intervals, the air speed variation trends had significant difference. The uniformity of airflow distribution in CZ, which was defined as ratio of standard deviation of air speed to the mean, was increased by application of the deflectors. The uniformity was positively related to height and negatively related to the interval of deflectors. [ABSTRACT FROM AUTHOR]

Provision of nest boxes is necessary for laying hens, especially in non-cage systems. This study investigated the effects of nest width on nest utilization and mislaid eggs. Hy-Line Browns hens were transferred from conventional cages to perchery pens at 12 weeks of age. Two experiments were conducted to mutually verify the hypothesis that narrowing group nests would improve nest utilization and reduce mislaid eggs. In experiment 1, group nests of 150 cm wide in two pens were partitioned at intervals of 50 cm and 37 cm, respectively. In experiment 2, partition panels were removed after acclimation. The number of mislaid eggs and nest eggs in each pre-set section were compared. Results indicated that narrowing group nests had positive effects on improving usage uniformity and efficiency of group nests. Nest eggs were more evenly distributed on the egg belt in both narrowed group nests, which was indicated by the significant decrease of variance among different sections (p<0.001). The proportion of mislaid eggs decreased by 3.5% in 37 cm treatment (p<0.05) and 4.7% in 50 cm treatment (p<0.001), respectively. As expected, reuse of the 150 cm group nests after removal of partition panels lowered the usage uniformity of group nests. A growth of three percentage points was found for the proportion of mislaid eggs after removing the partition panels in 50 cm treatment. The present results indicated that it is the width of the nest box that works for a better use of group nests. In conclusion, adding partition panels at intervals of 50 cm and 37 cm in group nests both are effective on nest usage and decreasing the occurrence of mislaid eggs. [ABSTRACT FROM AUTHOR]

As a result of the unprecedented highly pathogenic avian influenza (HPAI) outbreak in the U.S. in 2014-2015, some egg producers in the U.S. started using inlet air filtration to reduce the risk of disease transmission by air into hen houses. The removal efficiency of particulate matter (PM), the carrier of airborne pathogens, by such filtration systems has not been investigated. Therefore, this field study was conducted to evaluate the PM removal efficacy of an electrostatic air filtration system (consisting of a low-grade air filter and an electrostatic particle ionization, or EPI, system) installed at the inlet of a commercial high-rise hen house. The evaluation was performed in two test rounds over a one-year period. Results showed that average PM removal efficiencies in round 1 (spring to summer) and round 2 (late fall to spring) were respectively 66% and 29% for PM1, 66% and 30% for PM2.5, 66% and 31% for PM4, 68% and 36% for PM10, and 68% and 45% for total PM. Removal efficiency became unstable when the EPI system was inactive (i.e., when solely relying on the filter for PM removal). House static pressure and ventilation rate indicated considerable clogging of the filter media by dust accumulation and the need for replacement after ~16 weeks of use in the spring-to-summer sampling period (round 1); however, clogging was not an issue during the entire late fall-to-spring sampling period (24 weeks, round 2). The appearance of the filter changed gradually as dust accumulated with time, which can be captured by image analysis and used to judge filter dirtiness and lifespan. The findings of this field study provide insight into the efficacy of PM removal by such a low-cost air filtration system, which will help egg producers in their decision-making for disease prevention strategies. [ABSTRACT FROM AUTHOR]

This paper is an integral part of the special publication series that arose from the multidisciplinary and multi-institutional project of the Coalition for Sustainable Egg Supply (CSES). The CSES project involves 3 housing systems for egg production at the same research farm site in the Midwest, USA, namely, a conventional cage (CC) house, an aviary (AV) house, and an enriched colony (EC) house. The CC house (141.4 m L × 26.6 m W × 6.1 m H) had a nominal capacity of 200,000 hens (6 hens in a cage at a stocking density of 516 cm2/hen), and the cages were arranged in 10 rows, 8 tiers per cage row, with a perforated aisle walkway at 4-tier height. The AV house (154.2 m L × 21.3 m W × 3.0 m H) and the EC house (154.2 m L × 13.7 m W × 4.0 m H) each had a nominal capacity of 50,000 hens. The AV house had 6 rows of aviary colonies, and the EC house had 5 rows of 4-tier enriched colonies containing perches, nestbox, and scratch pads (60 hens per colony at a stocking density of 752 cm2/hen). The overarching goal of the CSES project, as stated in the opening article of this series, was to comprehensively evaluate the 3 egg production systems from the standpoints of animal behavior and well-being, environmental impact, egg safety and quality, food affordability, and worker health. So that all the area-specific papers would not have to repeat a detailed description of the production systems and the management practices, this paper is written to provide such a description and to be used as a common reference for the companion papers. [ABSTRACT FROM PUBLISHER]

The airflow in and around poultry houses was studied numerically with the goal of determining the disease spread characteristics and comparing two ventilation schemes. A typical manure-belt laying hen egg production facility was considered. The continuity, momentum, and energy equations were solved for flow both inside and outside poultry houses using the commercial computational fluid dynamics (CFD) code FLUENT. The geometry was constructed by making some simplifying assumptions, such as two-dimensionality. The spread of virus particles was considered analogous to diffusion of a tracer contaminant gas, in this case ammonia (NH3). The effect of thermal plumes produced by the hens in the poultry house was also taken into consideration. Two ventilation schemes with opposite flow directions were compared. Contours of temperature and contaminant mass fraction for both cases were obtained and compared. The analysis shows that ventilation and air quality characteristics were much better for the case in which the airflow was from bottom to top instead of from top to bottom (top to bottom is how most current poultry houses are configured). This has implications for air quality control in the event of epidemic outbreaks. Decreased contaminant spread to downwind poultry houses was observed in the bottom-to-top airflow scheme. [ABSTRACT FROM AUTHOR]

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Nesting structures for ground-nesting waterfowl may be an effective technique for increasing nesting success in regions in which nest success is below the 15% threshold needed to maintain a stable population. We studied the occupancy rate of artificial nesting structures called hen housesTM by Mallards (Anas platyrhynchos) nesting in two different wetland habitats, beaver ponds and sewage lagoons, in eastern Ontario during 1999-2001. We hypothesized that, because natural cover was sparse on sewage lagoons, Mallards would occupy hen houses at a higher rate on sewage lagoons than on beaver ponds. However, of the 248 hen houses distributed between beaver ponds and sewage lagoons, none was occupied by waterfowl. Common Grackles (Quiscalus quiscula) were the only avian species that nested in hen houses. However, Mallards successfully nested directly under several structures (n = 6) when water levels were low enough to expose the ground beneath them. Mayfield daily nest survival estimates for Mallards nesting in natural cover were similar on sewage lagoons and beaver ponds for all years (mean = 0.99) and were higher than most published estimates. Factors such as nesting cover, predation pressures, and structure design and material may influence the use of artificial hen houses and should be considered when planning a hen house program outside of the Prairie Pothole Region.