Compost dairy barns in Minnesota: A descriptive study

Compost barns have been receiving increased attention as an alternative housing system for dairy cattle. The first compost dairy barn was built in Minnesota in 2001 by a producer with the goal of improving cow comfort, cow health and longevity, and ease of completing daily chores. A descriptive study was conducted from June 2005 to September 2005 on 12 compost barns in Minnesota in order to describe the building layout, collect building dimensions, characterize the bedding material, and observe barn management practices that were used on these dairies. The layout of the compost barn typically consisted of a large bedded pack surrounded by a 1.2-m concrete wall and a concrete feed alley. Walkways allowed cows and equipment to freely access the pack from the feed alley. The bedded pack was aerated twice a day. The average pack (resting) area of the 12 compost barns was 8.6 (±2.6) m² per cow. Bedding temperatures averaged 42.5 °C (±7.6). Bedding material contained 2.54% (±1-0.59) N, 19.5 (±7.5) C:N ratio, 3247 (±1067) ppm P, and 15,270 (±4830) ppm K. The bedding temperatures and chemical characteristics indicate that the bedding material was not composting, however, the aerated pack was biologically active. The largest concern expressed by the producers was the cost and availability of bedding, especially as additional compost dairy barns are built. Overall, producers were very satisfied with their choice in housing system.