Ammonia (NH3) emissions from poultry animal feeding operations (AFOs) have caused health and environmental concerns. Current NH3 emission measurement methods are accurate and reliable but also time-consuming, expensive, and impractical for most animal facilities. In this study, an alternative mass balance method was developed to effectively predict NH3 emissions from manure belt (MB) poultry layer facilities. This method can eliminate the need for tracking manure flow rates in traditional mass balance analyses for estimation of ammonia nitrogen (NH3-N) emissions. It was applied to three MB layer poultry houses in Ohio, with approximately 160,000 hens in each house, and validated using continuous NH3 emission measurement data. Feed, manure, and egg samples were collected from the three houses in different months over a year to evaluate possible seasonal variation in NH3 emissions from the poultry houses. The estimated NH3-N emissions from houses 1, 2, and 3 were 0.394 +/- 0.143, 0.293 +/- 0.1, and 0.284 +/- 0.129 g NH3-N hen(-1) d(-1), respectively, and the measured NH3-N emission rates were 0.200 +/- 0.067, 0.220 +/- 0.036, and 0.237 +/- 0.211 g NH3-N hen(-1) d(-1), respectively. These results are comparable with NH3-N emission rates published in the literature (0.024 to 0.592 g NH3-N hen(-1) d(-1)). A statistical comparison of the measured and estimated NH3-N emissions showed that the root mean square error (RMSE), normalized mean square error (NMSE), and fractional bias (FB) were 0.179 g NH3-N hen(-1) d(-1), 0.426, and 0.457, respectively. These statistical parameters indicated that the estimations were acceptable according to the criteria of NMSE < 0.5 and FB < 0.5. The results showed that this alternative mass balance method could be used to estimate NH3-N emissions from MB poultry layer houses. However, the method estimates total nitrogen gas emissions, which is an upper limit of NH3-N emissions. A minimum of 22 sampling and modeling events is suggested for reliable estimation of NH3-N emission factors for MB poultry layer houses using the alternative mass balance method with a 90% confidence level (alpha = 0.1) and a maximum error of 15%
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机译：家禽饲养业务（AFO）排放的氨（NH3）引起了健康和环境问题。当前的NH3排放测量方法准确，可靠，但又耗时，昂贵且对于大多数动物设施不切实际。在这项研究中，开发了一种替代的质量平衡方法来有效预测粪肥带（MB）家禽层设施中的NH3排放量。该方法可以消除传统质量平衡分析中用于估算氨氮（NH3-N）排放的跟踪粪便流速的需要。它被应用于俄亥俄州的三个MB层禽舍，每个禽舍中约有16万只母鸡，并使用连续的NH3排放测量数据进行了验证。在一年中的不同月份中，从这三个鸡舍收集了饲料，粪便和鸡蛋样品，以评估禽舍中NH3排放量的可能季节性变化。从房屋1、2和3估算的NH3-N排放量分别为0.394 +/- 0.143、0.293 +/- 0.1和0.284 +/- 0.129 g NH3-N hen（-1）d（-1），测得的NH3-N排放速率分别为0.200 +/- 0.067、0.220 +/- 0.036和0.237 +/- 0.211 g NH3-N hen（-1）d（-1）。这些结果与文献中公布的NH3-N排放速率相当（0.024至0.592 g NH3-N hen（-1）d（-1））。对测量的和估算的NH3-N排放量进行的统计比较表明，均方根误差（RMSE），归一化均方误差（NMSE）和分数偏差（FB）为0.179 g NH3-N hen（-1）d（ -1），0.426和0.457。这些统计参数表明，根据NMSE <0.5和FB <0.5的标准，这些估计是可以接受的。结果表明，这种替代的质量平衡方法可用于估算MB家禽蛋鸡舍的NH3-N排放。但是，该方法估计的总氮气排放量是NH3-N排放量的上限。建议使用替代质量平衡方法，以90％的置信度（alpha = 0.1）和最大误差15％的可靠性，至少估计22个采样和建模事件，以可靠地估计MB家禽蛋鸡舍的NH3-N排放因子。
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