Universidade Federal de Viçosa, Departamento de Engenharia Agrícola, Av. Peter Henry Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brazil.
Universidade Federal de Lavras, Departamento de Engenharia, Av. Doutor Sylvio Menicucci, 1001, Aquenta Sol, 37200-000 Lavras, MG, Brazil.
An Acad Bras Cienc. 2023 Jul 17;95(suppl 1):e20220415. doi: 10.1590/0001-3765202320220415. eCollection 2023.
In Compost-Bedded Pack Barn (CBP) systems, air velocity is linked with the thermal comfort of housed dairy cattle and bedding quality and, therefore, assessing ventilation efficiency is essential. In this context, the objective of this study was to evaluate and characterize dependence and spatial distribution of air velocity at the 1.5 m height (vair,M) and at bedding level (vair,B) in an open CBP system with positive pressure ventilation. The study was conducted in 2021, in a facility located in the Zona da Mata region, Minas Gerais, Brazil. The facility area was divided into a mesh composed of 55 equidistant points, where vair,M and vair,B data were collected in the morning (09:00 a.m.) and afternoon (03:00 p.m.) periods, during three weeks in Brazilian winter. Geostatistics techniques were used to assess dependence and spatial distribution. In both periods evaluated, there were a strong occurrence of spatial dependence and non-uniform vair,M and vair,B distributions. The vair,M and vair,B values were lower than recommended (1.8 m∙s-1) in more than 65.0% of the area. Adequate ventilation levels were observed only in the first 20.0 m of the facility, from Southeast to Northwest, because of the fan lines present.
在堆肥卧床饲养（CBP）系统中，空气速度与饲养奶牛的热舒适度和垫料质量有关，因此，评估通风效率至关重要。在这种情况下，本研究的目的是评估和描述在具有正压通风的开放式 CBP 系统中，1.5 米高度（vair，M）和垫料层高度（vair，B）的空气速度的依赖性和空间分布。该研究于 2021 年在巴西米纳斯吉拉斯州 Zona da Mata 地区的一个设施中进行。该设施区域被划分为一个由 55 个等距点组成的网格，在巴西冬季的三周内，分别在早上（上午 9 点）和下午（下午 3 点）时段收集 vair，M 和 vair，B 数据。地统计学技术用于评估依赖性和空间分布。在所评估的两个时段，都存在空气速度的空间依赖性和不均匀分布。在超过 65.0%的区域，vair，M 和 vair，B 值低于推荐值（1.8 m∙s-1）。由于存在风扇线，仅在设施的前 20.0 米范围内，从东南到西北，才能观察到适当的通风水平。
