Managing winter housing to help control mastitis

What better time than winter to assess whether your buildings and system are contributing to your herd’s mastitis?

Dairy producers can congratulate themselves on the progress made in mastitis over recent decades. Since the days of the old 5-point plan, introduced in the 1960s, the incidence of mastitis has taken a significant downturn. While 150 cases per 100 cows per year may have been commonplace when the plan was introduced, incidence has dropped to nearer 32 cases per 100 cows per year for a 200 cow herd.

Efforts in the early scheme were focussed on contagious pathogens which tend to colonise the teat and are generally spread from cow to cow through the milking process. These bugs have generally been well controlled by tried-and-tested milking routines, and adherence to strict hygiene practices in the parlour.

But while the bugs which cause contagious mastitis have diminished in their relative importance, those which lurk in the environment have taken on a leading role. These pathogens are present in manure, bedding and standing water and can be transferred to cows from the parlour and collecting yard environment or between milkings, when the cow is loafing, eating or lying down.

A recent survey has shown that the bacteria most commonly isolated from clinical mastitis samples are Streptococcus uberis and Escherichia coli, both known to be environmental pathogens which thrive in manure and poorly maintained bedding.

As we reach the halfway point through winter, it seems an appropriate time to review conditions in the winter-housed environment and suggest some changes which could help cut the spread of environmental pathogens in the final weeks before turnout. 

Dr Steph Small, dairy sector veterinary advisor at MSD Animal Health, says this can be brought back to basics.

Dry cow housing

Dry cow housing is as good a place to start as any, but on many farms it is also the least well-managed.

“Out of sight and out of mind is too often the philosophy behind dry cow accommodation, yet this period is at least as crucial as the lactation when it comes to reducing the incidence of mastitis,” she says.

Advice on dry cow housing will vary according to system, but since loose housing on straw is commonplace, it’s worth considering best practice for this type of yard management.

“Straw tends to support higher levels of streptococcal bacteria than other bedding materials, so it’s little surprise that studies have found higher mastitis incidence in straw-bedded cattle than those in cubicles,” she says. “But since the best straw-yarded cattle do better than the worst cubicled cows, it’s clearly possible to make the system work.

Stocking density can impact on many environmental parameters, often increasing temperature and humidity, increasing the requirement for ventilation and diminishing hygiene. So, it’s important to meet the recommended targets of allowing at least 7.5 m²/cow for lying and at least 3.0 m²/cow for loafing and feeding. These requirements could be higher if yards are not well-designed.

The lying area should ideally be rectangular for efficient use of space as cows prefer to lie close to peripheral walls than in the middle of a yard,” she says.

“The feeding and loafing area should be free from bedding and scraped at least twice a day to reduce soiling of the feet with manure."

As for the bedded area, Dr Small says this must be fully cleaned on a routine basis and straw added daily.

“It’s not a case of waiting for the yard to look bad before it is cleaned, but rather scheduling a regular total clean-out, ideally followed by disinfection, at least every four to six weeks.

Areas around water troughs may need more regular attention and troughs should ideally be located in the loafing or feeding area rather than on bedding where they could increase the burden of environmental bacteria,” she adds.

Cubicle housing

Cubicles require a different approach whether used to house lactating or dry cows.

“There’s a minimum requirement for one cubicle per cow and if there’s less, mastitis and other diseases are likely to increase,” she says. “There’s also plenty of evidence that lying times decline when there’s less than one cubicle per cow, which can in turn lead to reduced milk yields.”

She urges producers to also check whether all cubicles are being used, she adds: “There’s a good argument for having 5% more cubicles than cows, rather than one-for-one which should be an absolute minimum.

Suffice to say that poorly designed and managed cubicles can lead to poor occupancy, wet and soiled cubicle beds and increased risk of mastitis as well as other problems such as lameness and physical damage to the cows,” she says.

“The best herdsman manually scrape soiled cubicles each time the cows are out for milking and also keep passages scrupulously clean,” she says.

However, she also points out that cleanliness may be related to animal health and nutrition as well as housing conditions.

Avoid stress

“This leads to the all-important avoidance of stress,” she says. “This will be assisted by appropriate nutrition to achieve good rumen fill, body condition and faecal scores, as well as the quiet handling of cattle and keeping social groups stable.

A calm environment will not only reduce the soiling of the cow and the immediate infection we know this can cause, but a lack of stress is one of a number of factors which can affect a cow’s natural immune defence mechanisms, helping her fight infection,” she says.

Advising farmers to contact their vet if they suspect environmental pathogens are affecting their herd’s udder health, she also suggests making a team effort involving everyone who works on or for the farm.

“It often pays dividends to get several advisors in the same room at the same time to assess all risk factors for mastitis, so consider inviting your nutritionist and housing advisor along too,” she says. 

“The costs of any interventions could initially appear daunting, but get the right advice and make sure it’s implemented and you’ll cut the costs associated with mastitis and its treatment and it won’t take long to earn the money back.”