J. S. Hogan 1
K. L. Smith
The Ohio State University Department of Animal Sciences
Bacterial counts in untreated sawdust bedding were compared with those in sawdust bedding after the addition of lime and after daily replacement of bedding in the back one-third of the stalls. Addition of 2.2 lbs. of lime to 22 lb. of sawdust reduces gram-negative bacteria, coliforms, Klebsiella spp., and streptococci prior to use as bedding. Sawdust treated with lime also showed decreases in bacterial counts when compared with sawdust that was replaced daily and control bedding after one day in the stall. The decrease in bacterial populations was related to an increase in bedding pH. Mean pH in sawdust that contained lime was greater prior to use and was greater after day one in the stall compared with other treatments. After two and six days in stalls, bacterial counts and pH were similar among treatments. Dry matter content of bedding did not differ among bedding treatments. Bacterial counts in bedding were positively correlated with teat skin swabs. Gram-negative bacterial and Klebsiella spp. counts on teat swabs were lower for cows housed on bedding treated with lime on day two compared with those cows housed on control bedding and bedding that was replaced daily. Addition of lime to sawdust in the back one-third of the stalls caused a decrease in exposure of teats to environmental mastitis pathogens in bedding for one day.
1 For more information, contact at: The Ohio State University, Ohio Agricultural Research and Development Center, 302 Pounden Hall, 1680 Madison Ave., Wooster, OH 44691; 330-263-3801; e-mail: hogan.4@osu.edu