The objective of the study was to determine whether, under controlled conditions, bedding materials vary in their ability to support growth of different environmental pathogens independent of the presence of feces, urine, or other contamination. Five sterilized bedding materials (fine hardwood chips, recycled dried manure, chopped newspaper, softwood sawdust, and chopped straw) and three bacterial species (Escherichia coli, Klebsiella pneumoniae, and Streptococcus uberis) were used for a total of 15 bedding/bacteria combinations, replicated in three trials. Samples were incubated at 37°C, and bacterial counts were determined over 5 d. Rapid growth was seen in straw and recycled manure, some growth occurred in hardwood chips, and a rapid decline in bacterial counts was observed in paper and softwood sawdust. In general, K. pneumoniae and E. coli showed more rapid growth or less rapid decline than did S. uberis. These results demonstrate that clean, damp bedding may support bacterial growth and suggest that high bacterial counts under barn conditions are influenced by factors more complex than type of bedding used.
Bibliographical noteFunding Information:
Received September 16, 1985. 1Journal Article Number 14,600, University of Minnesota Agricultural Experiment Station, St. Paul. 2R esearch was supported in part by a grant from the University of Minnesota Computing Center. This research was a contribution to the North Central Regional Project NCl19, Improving Dairy Herd Management Practices, in partial fulfillment of the requirements for an M.S. degree. Department of Animal Science. 4 Department of Large Animal Clinical Sciences. s Department of Applied Statistics.