Animal Industry Report

Extension Number

ASL R2322



Summary and Implications

This summary provides data regarding characteristics (dry matter content and environmental mastitis pathogen counts) of separated manure solids following composting and usage on mattresses (North free stall barn) and deep bedded compost freestalls (2 South freestall barns) in an Iowa dairy herd. Dry matter content of fresh separated solids was 20-25%, with composted solids being 20-40% when stored outside (variable due to weather) and 30-50% when stored in a hoop building. Dry matter content of separated solids once in stalls increased to 60-80%. Composting resulted in coliform bacteria levels < 10 2 (detection levels) but levels of all bacteria were elevated to baseline stall values following < 12 hr. time in stalls. Cow comfort, cleanliness, and feet and leg health were excellent on the bedded manure solids. SCC remained constant or declined following use of separated with no associated increases in clinical mastitis. Two clinical mastitis outbreaks were seen during the trial but not correlated to bedding bacterial counts. The first outbreak was associated with coliform counts in bulk tank milk > 200 CFU indicating weakness in milking management and teat end cleanliness prior to unit attachment. The second outbreak coincided with a nutritional management problem and a mild acidosis situation. This data shows that composted manure solids can provide a comfortable, effective bedding source if a consistent product is generated and managed properly, and stall, alley, and milking management areas are optimized.

Copyright Holder

Iowa State University