Thermal Environment, Ammonia Concentrations, and Ammonia Emissions of Aviary Houses with White Laying Hens

Abstract

Maintaining comfortable thermal environments and good indoor air quality is essential to ensuring optimal production performance, welfare, and health of animals. Alternative laying-hen housing systems are being adopted by some egg producers in the U.S. However, information on indoor thermal and aerial environments of such alternative housing systems is meager. This article reports a one-year monitoring of thermal conditions (air temperature and relative humidity or RH) and ammonia (NH 3 ) concentrations and emissions of four aviary laying-hen houses (same dimensions, manure belt plus litter floor systems, 50,000-hen capacity each) at a commercial farm in the Midwest U.S. Carbon dioxide (CO 2 ) concentrations at the air inlet and near the exhaust fans were measured and used, along with literature values of the metabolic rates of the hens, to estimate building ventilation rate (VR). The results show that indoor temperature, RH, CO 2 concentration, NH 3 concentration, and VR of the four houses (mean ±standard deviation) were 23.4°C ±0.3°C, 64% ±3%, 1520 ±87 ppm, 5.2 ±0.4 ppm, and 4.5 ±0.6 m 3 h -1 hen -1 , respectively. The highest daily mean NH 3 concentration was 13 ppm (and 20 ppm within the day) in winter. The NH 3 emission rate was 0.14 ±0.01 g d -1 hen -1 . These values of NH 3 concentrations and emissions were lower than those reported for European aviary houses. The NH 3 emissions of the monitored aviary houses in this study are comparable to those of U.S. manure-belt cage houses, but are much lower than those of U.S. high-rise cage houses. The magnitude of NH 3 emissions observed in this study was consistent with that of similar aviary houses with brown hens in another extended field measurement in the same region.

Reduction of Particulate Matter and Ammonia by Spraying Acidic Electrolyzed Water onto Litter of Aviary Hen Houses: A Lab-Scale Study

“…According to the results of this study, adjusting the water pH value to 5 or 3 would be conductive to reducing NH 3 generation in the hen house and thus mitigate NH 3 emissions. The recommended AEW spray dosage of 25 mL kg ) can be prepared by diluting electrolyzed water (EW) with a higher FC concentration and adding a regular acid (e.g., phosphoric acid) to it (Zhao et al, 2013a. For our research, EW with a high FC concentration (up to 1000 ppm) can be generated with the electrolyzer developed by our group at a cost of less than $100 .…”

“…Aviary hen housing is a typical cage-free system being adopted in the U.S. and Europe as an alternative housing operation (Hannah et al, 2011;Xin et al, 2011;Zhao et al, 2013a). Aviary hen housing offers hens the opportunities to exercise their natural behaviors (i.e., perching, dustbathing, foraging, and laying eggs in a nest) and more space to do so as compared with conventional cage systems.…”

Semi-Continuous Air Sampling versus 24-Hour Bag Samples to Evaluate Biofilters on a Swine Nursery in Warm Weather

“…The PMU used 24 min purging and 6 min sampling cycles, measured the concentration every second, and recorded an average every minute. Zhao et al (2013) used PMU to measure NH 3 and CO 2 concentrations in laying hen barns. For the study by Zhao et al (2013), PMU were programmed to sample ambient air for 20 min and barn air for 10 min.…”

“…Zhao et al (2013) used PMU to measure NH 3 and CO 2 concentrations in laying hen barns. For the study by Zhao et al (2013), PMU were programmed to sample ambient air for 20 min and barn air for 10 min. Because of the sampling system response time, only the last 2 min of data of each sampling period were used to determine NH 3 and CO 2 concentrations (Zhao et al, 2013).…”

“…For the study by Zhao et al (2013), PMU were programmed to sample ambient air for 20 min and barn air for 10 min. Because of the sampling system response time, only the last 2 min of data of each sampling period were used to determine NH 3 and CO 2 concentrations (Zhao et al, 2013). Hayes et al (2013) used a multi-gas analyzer plumbed to four composited sample lines to measure NH 3 , CO 2 , nitrous oxide (NO 2 ), and methane (CH 4 ) concentrations in two side-by-side aviary layer houses.…”