Mastitis in early lactation

Mastitis in early lactation costs money but careful management in the last couple of weeks before calving can prevent many cases from occurring. George Ramsbottom, Teagasc Dairy Specialist shares his experience and advice here

Research shows that a mild case of mastitis costs €200 and over €700 in a severe case when all costs are included.  More milk is lost when the cow is infected in early lactation than when the infection occurs at a later stage.

In my experience, early lactation mastitis, which occurs in the first thirty days or so after calving, is a problem in individual herds.  Such mastitis is often found not in the first milking after calving but over the first two or three days after calving.  UK research shows that over half of mastitis cases occur within the first 100 days of lactation.

Environmental mastitis - why?

Cows are especially at risk of acquiring environmental mastitis in the two weeks either side of calving because at this time the cow’s immune system is at it’s lowest ebb.  Research has found that some cows teat ends never seal properly after drying off and in late pregnancy heifer teat ends (and also cows) often start to open as the udder ‘springs’ which makes them vulnerable to infection. Thus both cows and heifers are vulnerable to infection before calving. 

The bacteria involved

Mastitis occurring during lactation is typically caused by Staphylococcus aureus.  This bacterium is spread mainly through the milking machine.  Few cases of early lactation mastitis are caused by S. aureus unless an old infection from a previous lactation recurs. 

Two types of bacteria are most often associated with the mastitis that occurs shortly after calving.  They are:

• Streptococcus uberis - a bacteria that causes distinct clinical mastitis infection, where cows generally do not become very ill. This form of mastitis can result in very high SCC levels in early lactation – typically 5-8,000,000 cells/ml.
• Coliform bacteria of which coli is the most widely known. These bacteria can cause severe mastitis often resulting in the loss of the affected quarter if not of the infected cow. 

Most of the bacteria that cause mastitis in early lactation have one thing in common – all are principally bacteria of environmental origin.  Improving the environment of cows and heifers in late pregnancy will usually reduce the incidence of this form of mastitis.  What steps can you take now to improve the situation on your farm? 

Immediate tasks

• Clean dry cubicle beds are a must – clean the ends of cubicle beds twice a day from two weeks before the start of calving. Sprinkle cubicle lime at the ends of the beds daily to reduce bacterial contamination and dry the bed. Remove damp bedding material such as chopped straw or sawdust daily. 
• Cubicle passages cleaned twice daily from two weeks pre-calving to reduce the build up of faecal matter.
• Where cows are moved to straw bedded calving areas (maternity ward) shortly before calving, ensure that the bed is ‘freshened up’ daily and that stale beds are removed frequently. Contaminated straw beds are a prime source of the bacteria that cause environmental mastitis.  
• On farms where the problem is particularly prevalent, teat spraying the cows 3 times a week in late pregnancy (in the last 3 weeks or so before planned calving) can result in a reduced incidence of early lactation mastitis by reducing the bacterial population at the teat end in late pregnancy.
• Separate freshly calved from pregnant cows, if possible, to reduce the risk of contamination of cubicle beds with discharges. Better still, weather and ground conditions permitting, put freshly calved cows to grass as soon after calving as possible. 

Longer term tasks

• Good milking practises will ensure early detection of mastitis and prevent it spreading to other animals. Your milking machine, a vital cog, must have been tested and maintained in good working order. Start the year with new liners and rubberwear.
• If condensation is a problem, improve house ventilation. Sure signs of ventilation problems are discolouration of the roof purlins and water dropping onto cubicle beds.
• Record cases of early lactation mastitis (indeed of all mastitis cases) on the ICBF website. Doing so will allow you to build up a picture of the pattern of mastitis infection in your herd. Should a problem arise, good records will help you to determine the cause of the problem and the affected animals on your farm.
• Milk recording throughout lactation is a very useful method of identifying cows with a recurring mastitis problem and one that I strongly advocate as a method of keeping SCC levels under control. With the impending change in the regulations around antibiotic use, milk recording will be an essential tool when deciding on your dry cow treatment programme in 2022.

In Summary

In summary, cows in late pregnancy are especially vulnerable to infections leading to early lactation mastitis. These bacteria are widespread in the cow’s environment so good hygiene, dry cubicle beds and clean calving areas will help to reduce the risk of infection.

The Teagasc Dairy Specialists issue an article on a topic of interest to dairy farmers every Monday here on Teagasc Daily. Find more on Teagasc Dairy here