Mastitis Tip of the Month -- Clean and Dry Bedding
Dairy Pipeline: December 1999
Gerald M. (Jerry) Jones
Extension Dairy Scientist, Milk Quality and Milking Management
Conditions which cause dirty teats and teat ends, thus causing greater effort to clean them, contribute to increased mastitis as well as potential for frost bite during cold weather. Wet, dirty bedding is a good example. It takes more effort to get teats clean, and may even require washing with sanitizer beyond pre-dipping, also the additional effort required may create short cuts and teats just aren't clean enough when the milking unit is attached. Degree of contamination and wetness of bedding influence the number of bacteria in bedding and thus at the teat end. Drier bedding is usually associated with lower numbers of bacteria. Adequate dry bedding should be provided to keep free stalls, maternity pens, and loose housing clean, dry, and comfortable. Daily removal of wet and soiled bedding is recommended, especially the back one-third of free stalls. There should be 15-20 cows per calving pen and calving areas should be cleaned and sanitized after 1-2 calvings and bedded with straw, shavings, or sand. According to the National Mastitis Council, finely chopped organic bedding materials, such as sawdust, shavings, recycled manure, pelleted corncobs, peanut hulls and chopped straw, frequently contain very high coliform and streptococcal numbers and have been associated with an increase in mastitis. With clean, long straw, coliform numbers are generally low; but the environmental streptococcal numbers may be high. Attempts to maintain low coliform numbers by applying chemical disinfectants or lime are generally impractical because frequent, if not daily, application inorganic materials, such as sand or crushed limestone, are preferable because they do not support bacterial growth but could be a problem with liquid manure systems. Other factors which may have some influence on environmental infections include: dry cow treatment, immunization during the dry period, vitamin E and selenium supplementation, especially before calving, as well as ration balance for vitamin A, copper, and zinc. An effective teat dip should cover most of the teat. Cows should be encouraged to stay on their feet for a half hour after milking because the sphincter in the teat end takes that much time to close. Barrier teat dips may be useful under less than ideal conditions for preventing new environmental infections. HOWEVER, it all starts with teats that are relatively clean when cows enter the milking parlor and are CLEAN AND DRY when the milking unit is attached. For more information on Environmental Streptococcal and Coliform Mastitis, see Extension Publication 404-234 or consult the web page at http://www.ext.vt.edu/pubs/dairy/404-234/404-234.html.