Mastitis – An ever-changing, ever-present challenge

Mastitis was and still is one of the most significant diseases of dairy cows.

Mastitis – in plain words, the inflammation of the udder – is a painful and potentially fatal condition for the cow itself.

Udder health is a serious challenge to animal welfare, sustainability of milk production and the economic success of a dairy farm.

An inflamed udder produces milk less efficiently and invested resources yield less return.

An inflammation of the udder may make it necessary to administer an antibiotic treatment which is another point of concern.

A huge proportion of antibiotics administered in dairy farming are in fact being used to treat mastitis.

What is mastitis?

Mastitis is an infection. Pathogens, usually bacteria, are entering the udder from the outside, attach to the tissue within and cause a reaction of the immune system. The pathogens can enter the udder at different points of time:

1. While cows are lying, they are in contact with the bedding material and bacteria can enter the udder via the teat orifice
2. While cows are being milked the udder gets in direct contact with hands of milkers, tissues for cleaning and, for a long time and very intensively with parts of the milking machine

All these surfaces can harbour bacteria and an infection can occur rather easily.

Not every infection causes a clinical mastitis, as most bacteria will be eliminated quickly by the cow’s immune system, not causing further damage.

However, some bacteria are adapted to the udder and can stay, while others are capable of causing dramatic clinical signs that pass quickly.

Everything in between is possible – long infections and short ones, mild and grave symptoms, bacteria well adapted to the cow or not at all.

© Dairy Data Warehouse

It becomes clear that the term “mastitis” is simply describing the inflammation of the udder. As shown, there is not only one form of mastitis; in fact, it is a complex of very different diseases with very different consequences.

More than 20 years ago, Andrew Bradley, a widely recognised specialist in udder health, described bovine mastitis as an “evolving disease.”

What does this mean? It points to the fact that while we are changing and improving the way we keep dairy cows, the different types of mastitis also change and the appearance of mastitis constantly transforms.

Some decades ago, one would have described it roughly as follows; the udder may be swollen, the milk is changed and white clots are visible, sometimes the milk may look unlike milk altogether; this would happen “out of the blue”, at any given time and was treated as a singular event.

Today, mastitis may still look like this, but this clinical form has become less relevant.

It is just the famous tip of the iceberg and either the result or starting point of an invisible process. We understand today that actually subclinical i.e. non-visible forms of mastitis are bringing down efficiency and sustainability.

While the animals appear normal and healthy, the udder is in a state of inflammation nevertheless; therefore the tissue producing the milk is compromised and milk yield depressed.

The more often this happens and the longer these processes last, the more severe the consequences will be for animal, herd and farm.

Reducing the risk for inflammation and decreasing its duration is therefore important.

The critical transition period and its link to mastitis

A critical time for udder health is the transition period i.e. the time before or after calving with a duration of about six weeks.

In the dry period before calving, animals with an existing infection stand a good chance of clearing it.

On the other hand, this time period is also a time of high risk. Cows are facing various physical and environmental changes.

Before calving, the udder tissue gets prepared to produce milk and the protection of the dry period ceases.

Cows are also entering a phase of metabolic challenges when the organism prepares itself for the energy-demanding onset of lactation.

Cows will usually enter a period of energy shortage that is compensated by mobilisation of body fat. One of the many consequences this physiological process can have is a depression of immune function.

During this phase, animals may therefore be extremely sensitive to infections and the most critical part of the lactation cycle needs to be guarded well.

Preventing mastitis in your herd

Mastitis at the onset of lactation is critical. Not only are animals most sensitive in this period, the animal itself and its production are at special risk.

If the mastitis is not be recognised or if the animal is not being supported adequately, there is a risk of the infection persisting – the value of the cow gets compromised and she may need to be replaced prematurely.

In any case, an episode of clinical mastitis at the onset of lactation will depress the milk production over the rest of the lactation.

Changes in the transition management, special attention and support to the animal during this phase and, on herd level, improvements in animal management are options to manage the risk. The risk therefore needs to be identified early and reliably.

Research shows us that certain characteristics point to risks in metabolism and udder health even before calving – history of udder health problems and long lactations leading to metabolic stress are examples.

Therefore, data analysis is the key to a proactive udder health management.

A powerful and effective way to use data are data-based predictions which have become available to dairy farming.

 Knowledge, animal observation, data and technology can work together and should be used to proactively prevent mastitis, ensuring a sustainable, animal-friendly and efficient milk production with healthy cows.

Learn more on how to identify cows at risk of transition disease in the dry stage here.