Fashions
Sand Bedding. The bedding material that we recommend most for controlling environmental mastitis is washed sand. Ideally, bedding should be inorganic material that are low in moisture content and contain few nutrients for bacteria to utilize. Washed sand has little nutritive value to common mastitis pathogens, thus limiting their growth. Compared to organic materials such as sawdust, recycled manure, straw, and dirt, washed sand consistently contains fewer mastitis pathogens. Many free stall barns are forced to use organic bedding materials that are compatible with liquid manure handling systems. Little advantage is gained in using one organic material over the use of another. For example, straw tends to have highest streptococcal counts, while sawdust and recycled manure have highest coliform counts in comparisons among these bedding materials.
Improved Dry Cow and Maternity Housing. Housing and other environmental concerns for dry and maternity cows have historically been precluded by the comfort and housing needs of lactating cows. However, given the impact of intramammary infections acquired during the dry period on the subsequent lactation, providing cows with a clean and dry environment is not limited to during lactation.
One of the most dynamic areas of dairy husbandry is dry cow management. Greater emphasis is now placed on both comfort and nutrition of cows transcending from lactating to dry and back into the lactating herd. Parturition, lactation, mammary involution, and lactogenesis are each reproductive events that influence the susceptibility of the mammary gland to infection. Rates of new intramammary infections caused by environmental pathogens are greater during the dry period than during lactation. During the dry period, susceptibility to intramammary infection is greatest the two weeks after drying off and the two weeks prior to calving. Many infections acquired during the dry period persist to lactation and become clinical cases. Research has shown that 65% of coliform clinical cases that occur in the first two months of lactation are from intramammary infections that originated during the dry period. Streptococcal infections during the dry period account for 56% of clinical cases during the first two months after calving. Rate of intramammary infections during lactation is highest at calving and decreases as days in milk advances. Therefore, the thrust of herd management strategies for controlling environmental mastitis should focus on reducing intramammary infections during the dry period and early lactation.
Dry cow and maternity facilities should be managed similar to lactating cow housing. Dry cow areas should be well drained and free of excess manure. Dirt covered areas can expose cows to pathogen levels comparable to those in free stalls. Box stalls and loose housing areas should be cleaned to the foundation base regularly. Manure packs are to be avoided because they generally contain extremely high counts of pathogens dangerous to both dam and calf.