Recent extreme cold temperatures and windy conditions may have resulted in some skin chapping of the teats of dairy cows, making them more susceptible to Staph mastitis.
Alvaro Garcia, a South Dakota State University dairy specialist, says there's a correlation between the severity of the skin damage, the degree of colonization by Staphylococcus aureus, and the increased risk of mastitis. Research results have shown that ointment-treated teats had marginally higher concentrations of Staph. aureus than dipped teats. The results suggest that treating teat skin with ointments can actually be more "cosmetic” and may not reduce the incidence of intra-mammary infections.
"Although ointments are good skin conditioners, their use may be warranted before the skin is damaged by cold weather rather than for treatment,” Garcia says.
The use of post-milking teat disinfectant is the single most effective practice for reducing the incidence of contagious mastitis, Garcia noted. Teat dips containing 1 percent iodine and 10 percent glycerin have been demonstrated to reduce the number of new intra-mammary infections caused by Staph. aureus by close to 90 percent. To reduce the colonization of the skin it is important to teat dip and then blot the teats dry before the cows exit the parlor and are exposed to cold drafts.
According to the 2007 National Animal Health Monitoring System Dairy study, S. aureus is the most prevalent contagious mastitis pathogen in the country, and its prevalence (43% of all dairy farms) appears to be unrelated to herd size or region.
Due to the contagious nature of this bacterium, using gloves is a very important prophylactic practice. However, Garcia says, while nitrile disposable gloves cost as little as 40¢ per pair, nearly half of the dairies in the U.S. in 2007 still didn't use them. The costs per mastitis case are estimated as being close to $200 per cow, with these additional costs being due to reduced production, discarded milk, costs of replacements, additional labor, treatment, and veterinary expenses. To make matters worse, in trying to save costs by not purchasing gloves, there's a risk of spreading the infection to other cows.
Garcia says there are additional strategies to consider. The cows with Staphylococcal mastitis should be milked at the end of the milking shift with a separate milking unit, or group the animals into a separate string of "sick” cows. But only about one-third of the dairies in the U.S. take these preventive measures, Garcia says.