Effect of cubicle hood system on methane concentrations around the lying area in cold climate dairy cattle buildings

Abstract

There is scarcity of data on methane (CH4) concentration levels and other gas compositions around animals in commercial cattle barns, especially for developing technology for gaseous CH4 treatment. Consequently, use of biofiltration and catalytic combustion strategies as alternative enteric CH4 mitigation techniques remain concepts yet to be validated in real cattle barns. One of the major barriers to implementing these techniques is that they require close buildings, which is not the case for most cattle barns. Open cattle barns are frequently associated with excessive ventilation, resulting in low CH4 concentrations, which can reduce the cost effectiveness of CH4 treatment techniques. With the development of low-cost, low-CH4-concentration enrichment technologies still in their infancy, developing local ventilation systems at the animal level capable of collecting breath CH4 from cows prior to air mixing could be an option. Therefore, the effect of a cubicle hood system (CHS) with different air extraction techniques on increasing CH4 concentrations at the lying area were evaluated in natural and mechanically ventilated dairy cattle buildings during the winter in Norway. In both barns, the use of CHS increased CH4 concentrations under the hood at the lying area by 14-25 % compared to without CHS. The results obtained depended on the height of the CHS from the floor and effect of outdoor temperature on air exchange rate in the barns. In the naturally ventilated barn, the hourly mean CH4 concentrations under the cubicle hood ranged from 14-225 ppm, and 31-322 ppm in the mechanically ventilated building.

Keywords

• Cattle barn
• Enteric methane
• Lying cubicle
• Hood system
• Methane extraction, Methane enrichment