For optimal milk yields, premium udder health is a prerequisite. This is not always easy to achieve, and mastitis has a high rate of occurrence among Dutch dairy farms. However, mastitis is described worldwide as the most common production-related illness (Seegers et al. 2003). The average loss from a clinical udder infection is € 210 (varies between € 164 and € 235, depending on the month of lactation and type of germ).
On average, mastitis costs € 225 per case. Udder infections are particularly damaging in the first three months. The costs are then € 280 per case. € 121 production losses, € 63 premature mortality, € 50 for treatment and € 43 for non-delivered milk. In the fourth to the ninth month, the loss is € 170 per case (GD 2018). Figure 1 below shows clearly that milk production decreases with a clinical mastitis infection. This involves comparing a cow with mastitis with healthy cows and expressing the difference in energy-corrected milk. Week 0 is the moment of clinical mastitis symptoms. The blue line represents the cows in the first lactation, and the pink line the multiple cows with calf. The broken line is the line the researchers have established based on scientific studies. This shows that in this study, milk production of the so-called mastitis cows is well under the control group, although the difference is less than previous studies established (Seegers et al. 2003).
Deteriorating udder health is also a reason for forced removal of cows. The figures show that 20% of the cows removed prematurely were removed due to deteriorated udder health (GD 2018).
There are two manifestations of mastitis: clinical mastitis and sub-clinical mastitis. Clinical mastitis is easy to observe (red udder, flakes in the milk), but sub-clinical mastitis is less visible, despite the presence of a genuine infection. The cell count of the cow concerned is therefore also a way to trace sub-clinical mastitis. Sub-clinical mastitis can develop into clinical mastitis. That’s why it’s important to treat sub-clinical mastitis and prevent problems.
Mastitis literally means: inflammation of the udder tissue. This can be caused by different bacteria, including E.coli, Staphylococcus aureus and Streptococcus uberis. These bacteria penetrate the udder and then cause inflammation. Most infections take place during milking due for instance to poorly cleaned milking equipment, towels, hands, etc. Due to inadequate cleaning, milk from infected cows come into contact with the udders and milk of uninfected cows, causing healthy cows to become infected. Furthermore, there are also environmental factors that can cause mastitis. Examples include hygiene in the cowshed, the cubicles, the gratings, and so on.
Proper treatment starts with recognising the signals early on. Clinical mastitis can be recognised from the flakes in the milk, a hard and painful udder (often also swollen), a strongly raised cell count of the quart concerned, and in some cases fever. Sub-clinical mastitis is more difficult to recognise as there is little to nothing to be seen on the udder initially. And yet the cell count and conductivity of the milk are raised (Veearts 2018). Conductivity stands for the degree of dissolved salts in the milk. With an udder infection, the blood-milk barrier is damaged and sodium and chloride ions from the blood enter the milk. And conversely, potassium ions leave the milk and enter the blood. Due to a raised concentration of salts in the milk, the electrical conductivity of the milk increases. This can be measured during milking (Miltenburg et al. KNMvD).
Treatment of (sub-)clinical mastitis is often done using antibiotics. One key note here is that first the bacteria causing the infection must be identified. Carrying out such an examination means that the treatment using antibiotics is more targeted and the success of the treatment most likely. However, there are alternatives to antibiotics that ensure that a (sub-)clinical udder infection heals.
Usually these are products based on plant extracts with an anti-inflammatory effect. This type of products will not always prevent the use of antibiotics, but they can help to significantly reduce their usage, as long as they are applied properly. In addition, the use of udder care products is recommended as this type of product promotes the circulation of the udder, ensuring the more effective removal of bacteria and dead udder tissue.