Systematic evaluation of laying hen exposure to atmospheric ammonia
type: CreativeWork
description: Maintaining low atmospheric ammonia (NH3) concentrations in laying hen housing is a well-known challenge and recently has become the center of legislation for animal housing. In the winter months, poultry farm managers have to balance indoor temperature and environment (including atmospheric ammonia (NH3) concentrations) by adjusting the ventilation rates. To maintain the birds' thermal comfort, sometimes the ventilation rates are reduced, resulting in NH3 concentrations above the recommended concentrations. The United Egg Producers recommends atmospheric NH3 concentrations from below 10 ppm to a maximum of 25 ppm. Similarly, NIOSH recommends a time-averaged exposure limit of 25 ppm NH3 over an 8-h period for human safety. During extreme weather conditions, the NH3 concentrations in laying hen houses have been measured above these limits. A multi-disciplinary approach is needed to better understand the effects of NH3 exposure on laying hen health, production, behavior, and overall welfare. To better understand how NH3 affects laying hens, three studies were completed: long-term moderate concentration exposure, short-term high-concentration exposure, and preference/aversion behavior testing. The two exposure studies used a combination of measures, including pathology, immunology, and production. The preference testing was conducted in an environmental preference chamber that allowed the hens to move freely between four distinctly different ammoniated environments. The preference testing used measures of behavior, duration of occupancy, and the number of entrances to determine if hens displayed an aversion to the atmospheric ammonia. Finally, the data from all three of the studies was combined into a collective data set to apply a systems approach to evaluate for overall effects of NH3 concentration and duration. Long-term exposure was tested by housing the hens in either moderate NH3 (30 ppm) or fresh air (<5 ppm) for 25-50 wks. In the long-term exposure study, intra…
abstract: Maintaining low atmospheric ammonia (NH3) concentrations in laying hen housing is a well-known challenge and recently has become the center of legislation for animal housing. In the winter months, poultry farm managers have to balance indoor temperature and environment (including atmospheric ammonia (NH3) concentrations) by adjusting the ventilation rates. To maintain the birds' thermal comfort, sometimes the ventilation rates are reduced, resulting in NH3 concentrations above the recommended concentrations. The United Egg Producers recommends atmospheric NH3 concentrations from below 10 ppm to a maximum of 25 ppm. Similarly, NIOSH recommends a time-averaged exposure limit of 25 ppm NH3 over an 8-h period for human safety. During extreme weather conditions, the NH3 concentrations in laying hen houses have been measured above these limits. A multi-disciplinary approach is needed to better understand the effects of NH3 exposure on laying hen health, production, behavior, and overall welfare. To better understand how NH3 affects laying hens, three studies were completed: long-term moderate concentration exposure, short-term high-concentration exposure, and preference/aversion behavior testing. The two exposure studies used a combination of measures, including pathology, immunology, and production. The preference testing was conducted in an environmental preference chamber that allowed the hens to move freely between four distinctly different ammoniated environments. The preference testing used measures of behavior, duration of occupancy, and the number of entrances to determine if hens displayed an aversion to the atmospheric ammonia. Finally, the data from all three of the studies was combined into a collective data set to apply a systems approach to evaluate for overall effects of NH3 concentration and duration. Long-term exposure was tested by housing the hens in either moderate NH3 (30 ppm) or fresh air (<5 ppm) for 25-50 wks. In the long-term exposure study, intra…
author: Tucker, Christina Marie
language: en
keywords: Poultry, Laying Hen, Ammonia, Aversion, Preference Testing, Livestock Housing, Air quality, Systems Thinking, Animal Welfare
date published: 2021-03-05T21:42:50Z
date modified: 2026-07-22T22:24:50Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/109526