Increase Risk Of Mastitis In Dairy Cows

By Alvaro Garcia

The high winds and extremely cold weather across South Dakota may increase the risk of Staph mastitis in dairy cows.  

"Current weather conditions may result in skin chapping of dairy cows' teats," said Alvaro Garcia, SDSU Extension Agriculture and Natural Resources Program Director & Professor. "There's a correlation between the severity of the skin damage, the degree of colonization by Staphylococcus aureus, and the increased risk of mastitis."

Ointment may make matters worse

Garcia said that according to research, ointment-treated teats have 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," he said. "Although ointments are good skin conditioners, their use may be warranted BEFORE the skin is damaged by cold weather rather than for treatment."

The use of post-milking teat disinfectant is the single most effective practice for reducing the incidence of contagious mastitis, Garcia said.

Teat dips containing 1 percent iodine and 10 percent glycerin have been demonstrated to reduce by close to 90 percent the number of new intra-mammary infections caused by Staph. aureus.

"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," Garcia said.

According to the 2007 National Animal Health Monitoring System Dairy study, Staph. aureus is the most prevalent contagious mastitis pathogen in the country, and it is prevalent in 43 percent of all dairy farms.

The same study suggests that prevalence of Staph. aureus is unrelated to herd size or region.

Due to the contagious nature of this bacterium, using gloves is a very important prophylactic practice. "However, while nitrile disposable gloves cost as little as 40 cents per pair, nearly half of the dairies in the U.S. still do not use them," Garcia said.

Costs per mastitis case are associated with the additional costs of reduced production, discarded milk, costs of replacements, additional labor, treatment, and veterinary expenses.