Understanding mastitis and its control in dairy cows

A cow-milking session in a dairy farm. Mastitis is an inflammation of the cow's mammary glands. FILE PHOTO | NMG

What you need to know:

  • There are two types of Mastitis.
  • Most farmers are calm and relaxed thinking that they only have one case of clinical mastitis within their herd.
  • Clinical mastitis is detected using the visual clinical signs.
  • Sub-clinical mastitis is not visible so a California Mastitis Test(CMT) is used for detection on-farm, providing an immediate result and can be used by farmers.

Mastitis is the 2nd major reason for culling in dairy herds after infertility.

Mastitis is primarily a management problem and can be controlled. It also has a big economic impact on farms considering that there are high costs incurred due to: production loses, discarded milk, milk rejection at collection points, treatment costs, premature and high culling rates and deaths.

So what exactly is Mastitis?

Mastitis is an inflammation of the mammary glands. It has various forms, causes, effects and preventive measures.

Mastitis is caused by

• Physical Injury
• Chemical Damage
• Bacterial Infection (most common by far)

There are two types of Mastitis:

• Clinical mastitis
• Sub-clinical mastitis

A cow with sub-clinical mastitis will not show signs of disease from the udder.

Cardinal signs of clinical mastitis

The infected quarter shows signs of

• Swelling
• Painful to touch,
• Warm,
• Redness
• Loss of function
• Milk may have clots, flakes, discoloured serum or blood.

Most farmers are calm and relaxed thinking that they only have one case of clinical mastitis within their herd.

What they are not aware of is the possibility that more cows in the herd could be having sub-clinical mastitis.

Sub-clinical mastitis is the most expensive form of the disease as its signs are not visible to the naked eye.

Most sub-clinical mastitis cases that are not treated end up being clinical mastitis.

Diagnosis of mastitis

Clinical mastitis is detected using the visual clinical signs: cow not eating and drinking as usual, one quarter different from the others (red, swollen, hard and hot and painful to touch). Milk may be discoloured, have clots, flakes or even blood.

Sub-clinical mastitis is not visible so a California Mastitis Test(CMT) is used for detection on-farm, providing an immediate result and can be used by farmers.

It consists of a four-well plastic paddle each for the corresponding quarter of the cow to be tested. The foremilk is discarded, and then a little milk drawn into each well.

An equal volume of test reagent is added and then the sample is gently agitated and results are then read.

Treatment

Intramast LC tubes are available in the market for treating mastitis. It is best to get a Veterinary laboratory carry out a culture and sensitivity test so as to advise on the best drug to use.

Prevention and Control

1. Prepare cows properly for milking
Wash the udder with clean water and disinfectant. Always use teat dip solutions before milking as they lower the risk of new infections by 70 percent. Use single service paper towels, dry teats before machine-application or hand milking.

2. Dip each tea t after milking using a germicidal teat dip. Post-dips seal the teat ends temporarily for 6 to 8 hours. A must for long term mastitis control program

3. Segregate chronic mastitis cows, milk them last, cull when necessary. Cows with chronic mastitis serve as reservoirs of organisms and could infect susceptible cows.

4. Dry each quarter using dry cow treatment at drying off. This lowers the risk of clinical and sub-clinical mastitis during subsequent lactation

5. Keep cows’ clean, udders free from soil and manure by fencing off wet or swampy areas. Keep stalls bedded properly. Calving areas should be kept clean and properly bedded (straw preferred).

6. Properly feed and care for cows and provide wholesome water and mineral supplements.

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Dr John Muchibi is a Veterinary Surgeon and the Animal Health Manager at Elgon Kenya Ltd. Reach him through 0733715102 or e-mail him through [email protected]