MASTITIS IN DAIRY COWS
MASTITIS is inflammation of the udder, it may occur in lactating or non-lactating cows. It is caused by fungus-like micro-organisms.
It is a disease that affects one or all the divisions of the udder. The clinical signs depend on the nature of the causal organism.
The importance of mastitis lies in the large amount of loss that it causes in dairy herds and the danger to human health such as salmonellosis, tuberculosis and sore throat to mention but a few.
Under tuberculosis of the udder there is inflammation of the udder tissue between the acini that is small milk-conducting tubules, the latter are eventually obliterated.
Infection usually reaches the udder through the teat canal, it can also be through injuries to the skin and via the bloodstream. This pass, as mentioned, is another access to the udder tissue. Such injuries or cracks are usually caused by some slight mis-handling of the udder. It is this kind of damage, which easily occurs at the time of milking, against which every milker should guard if they understand the disease and the way it is spread.
To reduce or avoid incidences of mastitis, it well to establish a standard milking technique such as to take advantage of the natural phenomenon of let down or milk let down.
This is conditioned by associations of clanging of buckets, the smell of food or the massage applied before milking.
Once such a routine is taken any marked variation in such a routine will and shall interfere with the let down process.
Common sources of infection are badly maintained teat cups, the hands of the milker, rough handling of the udder, infected bedding particularly when the secretion from diseased quarters has been milked on to this and contamination by flies.
When infection has taken place there is some alteration in the size, shape or feel of the udder, sometimes with pain or tenderness. Milk yield is always affected and there may be visible changes in the milk.
These can be clots or flakes, blood, blood-staining or other colour changes and an unusual smell coming from the milk.
Depending on the type of organism affecting the udder, the milk coming out tend to have bright orange colour turning to dark brown and usually odourless.
The cow may have a normal or subnormal temperature, quarter becomes hard and painful after the onset of the symptoms. In some cases the milk may have a bad smell, is thick, greenish/yellow in colour and may have clots of blood in it. This type of mastitis is often seen in dry cows.
When mastitis occurs it can be mild in which a few clots are seen in the fore milk. They may appear at each milking. There are no adverse effects on the cow but milk yield will be lower than normal.
The acute situation is when the quarter is hot, swollen and painful. The milk is usually straw-coloured and sometimes stained with blood, the cow is off feed, upset and not cudding with high temperature.
At this stage the quarter can be stripped on two-hourly intervals and this has to be done into a vessel containing a disinfectant so that the germs are immediately destroyed.
The sub-acute is similar to acute but of shorter duration. Appetite is not entirely lost, quarter is less congested and painful. The chronic form can be a result of the last two mentioned.
The quarter is painless but more or less thickened and feels appreciably firmer than a normal quarter.
The milk secreted is ropy or like clotted cream without small. Otherwise the animal’s health is generally unaffected.
There is no certain cure, the goodness is modern remedies are very much more effective than those used many years ago. Mastitis is a practical job and every stockman must take it as his responsibility and prevention on the farm should be in the routine adopted.