Lactation education

Preparing cows for lactation success begins at the dry period

Mastitis can strike at any time, but research has shown that the early and late stages of the dry period are when dairy cows are most susceptible to newly acquired intramammary infections. The first two and last two weeks of the dry period represent the transition times in and out of mammary gland involution and can be characterized by high volumes of milk and colostrum. Preventive management approaches that address both of these periods are likely to be beneficial in reducing the incidence of mastitis in the dairy herd. Although there is no single program for mastitis control and prevention, here are some key management principles to consider when drying off:

• Employee training and compliance with dry-off procedures

Make sure your standardized dry off procedure has been recently reviewed with your veterinarian and management team. All salon teams and individual employees are prone to procedural drift and “training amnesia” without frequent reinforcement of knowledge. It is essential to provide basic training, follow-up and periodic retraining so that employees use up-to-date techniques. Since there is a high potential for introducing pathogens into the striate duct at dry off, attention to detail and consistent adherence to proper teat preparation and tube administration techniques can help make efforts more effective prevention.

• Determine your dry cow treatment strategy

Published research has shown that administration of an intramammary antibiotic targeting Gram-positive bacteria at drying off can treat existing subclinical infections and prevent new ones. As the industry moves away from general dry cow therapy towards increased adoption of Selective Dry Cow Therapy (SDCT) and more targeted use of intramammary antibiotics, not all farms are currently able to make this change without significant economic and animal welfare compromises. Determining a dry cow treatment strategy can prioritize antibiotics that are of lesser importance to human public health, balancing goals around judicious use with animal productivity, and should be tailored to the needs of your herd in consultation with a treating veterinarian.

• Seal the deal with teat sealant

Teat sealants are intended to supplement the cow’s natural keratin plug against the penetration of mastitis pathogens. Teat sealants have been shown to work by providing a physical barrier with or without dry cow antibiotics. Studies have shown that 25-50% of the herd of dry cows may not form a keratin plug within the first 40 days of drying off. In this case, dry cow herds may also benefit from the administration of an external teat sealant in addition to the internal teat sealant.

• Selection of vaccines

Coliform mastitis core antigen vaccines are an established industry practice that may reduce the severity of some Gram-negative mastitis infections during lactation in herds with a higher incidence of environmental mastitis pathogens. Careful timing is critical to the success of immunization, which reduces the severity of mastitis, culling, milk loss and mortality associated with E. coli in first calf heifers and multiparous cows.