There is a growing body of evidence that associates cow cleanliness, or hygiene, and mastitis. Cleaner cows are a lower risk for a mastitis incident than dirty cows.

Klebsiella, a leading cause of coliform mastitis, is a prime example of a pathogen that may be more prominent in a dirty environment. Manure in the alleys is one source of contamination of cows’ legs, which then come into contact with the udder while the cow is lying. Cow hygiene was the focus of two articles in a recent edition of the Journal of Dairy Science.

The first article evaluated the effects on the use of automatic alley scrapers on the cleanliness of slatted floors and the subsequent effect on cow cleanliness. The second article attempted to expand previous work and establish a relationship between cow hygiene and the presence of Klebsiella on the lower leg and udder (both before and after udder preparation). Both the cleanliness of the barn and cows were recorded in the study conducted at the Swedish University of Agricultural Sciences.

The automatic scrapers were run in one portion of the barn every two hours in the alley associated with the freestalls and every 3.5 hours in the alley associated with the feed alley. The amount of manure in these alleys was compared to another portion of the barn, which relied solely on the slatted floors for manure removal. Using the alley scrapers significantly reduced the amount of manure behind the freestalls and along the back wall of the feed alley. This reduction of alleyway manure resulted in cows with significantly cleaner teats and udders.

The second study measured the percentage of cows contaminated with Klebsiella across the range of hygiene scores. Swabs of cows from each hygiene score (on a 1 to 5 scale) were collected from the lower leg and the teats. Teat swabs were done prior to udder preparation for milking and again following the completion of preparation. Cleanliness was not associated with Klebsiella prevalence on the legs or pre-preparation udder; however, dirty udders were significantly more likely to be contaminated after udder preparation.


This demonstrates that Klebsiella remains on the teat and puts the cow at greater risk for infection when the teat sphincter is relaxed following milking. The combined results of these two studies suggest that the investment in alley scrapers can be one important aspect of maintaining or improving milk quality. Keeping alleyways cleaner leads to cleaner cows, which are at less risk for environmental mastitis.

—Excerpts from Miner Institute Farm Report, November 2008

Peter Krawczel
William H. Miner Agricultural Institute