Managing Free Stall Bedding Materials

Controlling the incidence of bovine mastitis is based on reducing the exposure of cows to mastitis pathogens in the environment. Bedding in stalls is very closely related to the bacterial exposure of the cows due to the fact that cows spend from 8 to 14 hours daily lying down with their udders in direct contact with the stall surface material. One important source of environmental mastitis pathogens that can be controlled, is bedding materials.

Samples taken from daily replacement stalls in a trial investigating recycled manure solids had lower coliform counts compared with deep pack stalls. This reduction was particularly seen in Klebsiella spp..
Samples taken from daily replacement stalls in a trial investigating recycled manure solids had lower coliform counts compared with deep pack stalls. This reduction was particularly seen in Klebsiella spp..

Product or Practice?

Bedding materials are primary sources of mastitis-causing environmental pathogens. Populations of these bacteria in bedding are related to the number of bacteria on teat ends and rates of clinical mastitis. Consequently, reducing the number of bacteria in bedding generally reduces the incidence of environmental mastitis in a herd. Environmental mastitis pathogens include coliforms and environmental streptococci. The primary transfer of these pathogens from the environment to teat ends does not occur during milking but between milkings. Coliforms and streptococci cannot live on teat skin for long periods of time. If these bacteria are present in large numbers on teat skin, it is the result of recent contamination from a source such as bedding. Therefore, the number of these bacteria on teat skin is most often a reflection of the cow’s exposure to the contaminated bedding.

A practical question to ask, when evaluating the nature of teat end exposure from bedding, is whether the focus should be on adapting to the use of specific products that reduce exposure or give attention to management practices which will minimize exposure. Ideally, bedding will be used that does not support bacterial growth; and management will emphasize management practices to prevent contamination and soiling of the bedding. Realistically, the bedding material selected for a farm and the extent that hygiene practices are employed to eliminate contamination of bedding in stalls often involve factors that result in less than ideal conditions.

Selection of Product

The criteria for the selection of bedding for dairy cows have changed drastically over the last 30 years. Complicating the assessment of disease risk attributed to bedding is the fact that bedding costs are one of the greatest variable expenses on the farm. Bedding materials historically were by-products of the dairy or other local industries that provided inexpensive and readily available product. Many deficiencies associated with some of these products were tolerated as a balance to their low cost and local accessibility. A major deficiency in organic by-products such as sawdust, corn stalks, and straw was their ability to cultivate mastitis pathogens. An increased awareness of the positive economic attributes of producing quality milk from healthy mammary glands caused a critical assessment of using organic bedding material compared with inorganic materials such as sand. Sand consistently has lower bacteria counts and gives increased cow comfort associated with its use compared with many conventional organic bedding materials. However, a major factor limiting the use of sand on