Reducing mastitis in your dairy herd

SALEM, Ohio —The unfortunate reality for dairy farmers is, “if you have a dairy farm, you probably have mastitis,” said Luciana Da Costa, Ohio State Dairy Extension Veterinarian.

In fact, according to a report released by the USDA in September 2016, producers on almost all surveyed U.S. dairies — 99.7 percent — reported having at least one case of mastitis during 2013. The report, Dairy 2014 — Milk Quality, Milk Procedures, and Mastitis on U.S. Dairies, also highlighted that clinical mastitis was detected in about one-fourth of all cows, 24.8 percent.

“Yes, 99 percent of farms probably have at least one case of mastitis on a farm a year,” said Amber Yutzy, Penn State Extension dairy herd health educator, in a response to the report’s findings. “Farms are pretty much bacteria-ridden,” she said.

The good news is, mastitis cases can be reduced by using good farm management techniques and experiencing a massive loss on your farm due to mastitis is not very likely.

According to the USDA report, almost three-fourths of cows with mastitis in 2013, 72.8 percent, were recovered and remained in the herd, and about one-fourth of mastitic cows were removed or sold from the herd. Less than 5 percent of all cows died as a result mastitis.

Mastitis affects the herd

Mastitis is an inflammation of the mammary gland caused most often by bacterial infections. “The problem with mastitis is everything that you have on the farm can be a risk factor,” said Da Costa. When cows are milked, the teat is opened and exposed to all kinds of bacteria that can get inside it, she said.

The bacteria can come from anywhere — from the bedding pack, the hands of milkers, and can be passed from cow to cow while they are using the same milking unit. Mastitis contributes to a decrease in production as well as profitability, said Yutzy.

“There is a loss of milk while that cow is being treated as well as treatment costs and labor,” she said. Affected cows may also experience a decrease in production over the course of their lactation. “If multiple cases of mastitis occur, the farmer starts to experience significant decrease in production across the herd,” said Yutzy.

Somatic cell count

A Somatic Cell Count (SCC) can give the farmer an indication of the health of an individual cow and the overall health the herd. “We consider an infected cow to have an SCC over 250,000 cells per milliliter,” said Da Costa. This doesn’t necessarily mean the cow has mastitis, it’s just an indicator that there is a problem.

“Usually, what (milkers) do in the parlor is strip some milk to check the appearance,” said Da Costa. Milkers are looking for clots or other alterations to the milk — discoloration, discharge, etc. — to determine if mastitis is the issue.

If there is just slight alteration to the milk, the cow may have a mild case of mastitis; if the milk is altered and the cow is not feeling well, the cow may have a moderate case of mastitis; and if the milk is bad (pussy, discolored, etc.), the udder is bad and the cow is ill, this is most likely a severe case of mastitis, explained Da Costa.

Determine the type

The next step is to determine what type of mastitis you are dealing with. Mastitis pathogens can be contagious — transferred from cow to cow — or they can be environmental. Culturing milk and sending a sample to a lab is the best way to determine what type of pathogens are affecting the herd and how the farmer will go about treating it.

“The number one thing I tell farmers is to culture their milk,” said Yutzy. “We teach a lot of on-farm culture techniques.” From there, you can determine if a cow needs to be segregated from the herd and milked separately or if some changes need to made to the housing environment.

Clean, dry and comfortable

“Keep cows clean, keep bedding clean and pay attention to detail,” said Yutzy. Make sure each cow has a clean, dry space to lay down, has access to food and water and make sure she is getting plenty or rest, said Da Costa.

The milking parlor

Using a pre- and post-milking teat disinfectants (predip and postdip) kills bacteria on teat surfaces. Iodine is the most common dip used in milking parlors, said Da Costa. “It’s so important to make sure the whole teat is covered,” she said.

“Leave the predip on for at least five seconds before wiping off, to kill that bacteria and keep it from getting into the teat.” Postdips can also be purchased with extra emollients during the harsh winter months to moisturize and prevent cracking and chapping of teats.

Da Costa advises against using water to wash the udder before milking. “When you wash, it is almost impossible to take everything out and then you are dripping and debris and bacteria can get into the gland,” she said.

“The idea is to have the cows clean as much as possible before those cows come into the parlor” by having clean bedding areas, she said.

Milking units

Milking units should also be functioning properly and tested regularly by a professional to prevent teat end damage. Blue or red colored teats or ring formations left on the teat after milking can be caused by poor pulsation, excessive vacuum, or incompatible liner or shell in the milking unit and should be corrected.

Unit malfunctions can also cause teat end damage or pin-point bleeding. Check hose connections and hose lines and have units tested.

Proper unit alignment and removal is also important to reduce chances of infections. Milker units should hang so all quarters milk evenly. The unit should be removed before every last drop is milked out. Over-milking will cause teat-end damage and increase infection rates.

Biosecurity

When buying new cows to add to the herd, make sure they are coming from a healthy herd. Herd SCC should be less than 250,000 cells per milliliter and individual cow SCC should be less than 200,000 cells per milliliter.

If SCC numbers are not available, do a Coliform Mastitis Test (CMT), said Da Costa. Results should come back negative if there is no mastitis. “If you can’t test, at least ask the farm owner if they have had any problems with mastitis in their herd,” said Da Costa.

Keep the purchased cows separated from the rest of the herd until they are proven noninfectious. Culture the bulk tank during the period those new cows enter the herd to monitor any changes to the herd SCC.

Non-lactating cows are less of a risk than mature cows because they have a lower exposure to the mastitis pathogen.

Management

Management and attention to detail is key, said both Yutzy and Da Costa. Make sure milking protocols are correct and make sure all employees know and understand them. “Consistency is a big issue,” said Yutzy.

“Make sure everyone is consistent and has a standard operating procedure so when mastitis does happen, everyone is handling the issue the same.”