The information below has been supplied by dairy marketers and other industry organizations. It has not been edited, verified or endorsed by Hoard’s Dairyman.
Brian Miller, D.V.M., Merck Animal Health
Dairy cows are most susceptible to new intramammary infections (IMIs) during the dry period. Cows are at greatest risk two to three weeks after dry-off and two to three weeks prior to calving. New IMIs acquired during this timeframe result in “carryover infections” into the next lactation which lead to an increased risk of clinical mastitis cases, inferior milk quality, production losses and early herd removal. Prevention can have a significant impact on a dairy producer’s bottom line. Clinical mastitis cases during the first 30 days of milk have been estimated to cost more than $400 per cow.
Three dry cow strategies that can help reduce IMI risk in the dry period include: 1) reduce bacterial exposure at the teat end; 2) use of dry cow treatment; and 3) enhance host and udder immune defense mechanisms.
# 1: Reduce Bacterial Exposure at the Teat End
Dry cows and springing heifers should be kept clean and dry to maintain cow comfort and minimize bacterial exposure. Mastitis-causing bacteria, such as coliforms and environmental streps, are shed in the manure in large numbers. These bacteria quickly contaminate the dry cow environment, particularly if there is overcrowding and/or warm environmental conditions.
Provide adequate resting space with loose housing and keep freestalls clean, dry and well maintained to lower bacterial numbers. Adequate