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首页> 外文期刊>Applied Engineering in Agriculture >Environmental characteristics and bacterial counts in bedding and milk bulk tank of low profile cross-ventilated, naturally ventilated, and compost bedded pack dairy barns.
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Environmental characteristics and bacterial counts in bedding and milk bulk tank of low profile cross-ventilated, naturally ventilated, and compost bedded pack dairy barns.

机译：低剖面交叉通风，自然通风和堆肥床上用品包装的奶牛舍的床上用品和牛奶大罐中的环境特征和细菌数。

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Low profile cross-ventilated freestall (CV) and compost bedded pack barns (CB) are two newer housing options for dairy producers in the Upper Midwest. The CV barns are fully enclosed facilities that rely on mechanical ventilation and typically use evaporative cooling for heat abatement during the warmer months. The CB barns are a loose housing system that is generally bedded with dry wood sawdust and tilled twice daily. The objectives of this study were to describe the housing system and assess air quality (aerial ammonia and hydrogen sulfide), air velocity, light intensity, temperature, and relative humidity in CV, CB, and naturally ventilated freestall barns (NV). This cohort study was conducted on 18 commercial dairy farms, 6 of each housing type, in Minnesota and eastern South Dakota. Farms were visited four times, once each season between January and November 2008. Ammonia, hydrogen sulfide, light intensity, and air velocity measurements were taken twice each visit with 10 measurements per sampling time. Aerial ammonia concentrations were significantly higher in CV barns than CB and NV barns (5.2, 3.9, and 3.3 ppm, respectively). Hydrogen sulfide concentrations were 18, 33, and 19 ppb in CB, CV, and NV barns, respectively. There was a trend for higher hydrogen sulfide concentrations in CV barns. Light intensity was significantly lower in CV barns than CB and NV barns (111, 480, and 392 lux, respectively). There were no differences in air velocity among the housing systems. The mechanically ventilated CV barns were warmer in the fall and winter than the CB and NV barns. When outside temperature was above 27 degrees C, CV barns were 2.9 degrees C and 3.0 degrees C cooler than CB and NV barns, respectively. No differences were seen in bedding or bulk tank bacterial counts among the housing systems. Although CV barns had significantly higher aerial ammonia and a trend for higher hydrogen sulfide concentrations than NV and CB barns, ammonia and hydrogen sulfide concentrations were below the threshold that would affect cow performance or human health. In conclusion, the three housing systems assessed had adequate air quality and ventilation to provide a safe environment for workers and animals.
机译：低矮型交叉通风的速冻（CV）和堆肥卧式包装谷仓（CB）是中西部上层乳制品生产商的两个较新的住房选择。 CV谷仓是完全封闭的设施，依靠机械通风，在温暖的月份通常使用蒸发冷却来减少热量。 CB谷仓是一个宽松的房屋系统，通常用干燥的木锯末铺垫，每天耕种两次。这项研究的目的是描述住房系统，并评估空气质量（空气中的氨和硫化氢），空气速度，光强度，温度以及CV，CB和自然通风的速冻牛舍（NV）中的相对湿度。这项队列研究是在明尼苏达州和南达科他州东部的18个商业奶牛场进行的，每个奶牛场有6个。在2008年1月至11月之间，每个季节对农场进行了四次访问，每个季节进行一次。每次访问都进行两次氨气，硫化氢，光强度和空气速度测量，每个采样时间进行10次测量。 CV畜舍中的空气氨浓度显着高于CB和NV畜舍（分别为5.2、3.9和3.3 ppm）。 CB，CV和NV谷仓中的硫化氢浓度分别为18、33和19 ppb。在CV谷仓中存在更高的硫化氢浓度趋势。 CV谷仓的光强度显着低于CB和NV谷仓（分别为111、480和392 lux）。住房系统之间的空气速度没有差异。机械通风的CV谷仓在秋季和冬季比CB和NV谷仓要温暖。当外部温度高于27摄氏度时，CV谷仓分别比CB和NV谷仓低2.9摄氏度和3.0摄氏度。住房系统之间的床上用品或大罐中细菌计数没有差异。尽管CV猪舍的空气中氨含量明显高于NV和CB猪舍，并且硫化氢浓度也有升高的趋势，但氨和硫化氢的浓度仍低于会影响奶牛性能或人体健康的阈值。总之，所评估的三个住房系统具有足够的空气质量和通风条件，为工人和动物提供了安全的环境。

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