By Donna Nkatha
Mastitis is a common, devastating disease affecting the dairy cows in many farms. The ailment results in enormous economic losses to the farmers whose cows are affected. Losses result from the cost of veterinary care, discarded milk, involuntary culling and the reduction in yields due to permanent damage to udders. Mastitis refers to the inflammation of the udder tissue and the mammary glands as a result of an immune response to the bacterial infection of the teat canal. Most common bacteria are Staphylococcus aureus. The disease can also originate from chemical, thermal or mechanical injury to cow’s udder. Severe acute mastitis can be fatal, and even the cows that recover may bear the consequences for the rest of their lactation periods.
Clinical features of mastitis in dairy cows
- Swelling of the udder
- General malaise that causes a reduction in cow mobility
- Burning sensation and pain while milking
- Affected teat appears red and lumpy
- An increase in body temperature
- Diarrhoea and dehydration
- Affected milk appears watery and contains clots and flakes
- Reduction in milk production
Modes of transmission
The contagious mastitis is commonly called the cow to cow transmission mastitis. The main habitation of bacteria responsible for mastitis is in teat lesions and the udder. The infection becomes transmitted to the dairy cows via milkers hands, milking machines, milk contaminated fomites during milking.
In environmental mastitis, the bacteria that result in mastitis are found in the cattle’s environment such as in beddings, water, soil or feaces. The infection from the environment can occur during contact of the teats between milking or at milking time.
Treatment of mastitis
On the detection of clinical mastitis, the cow is milked and out and administered the antibiotics directly into the infected glands. It is crucial that the teat is cleaned well; its tip swabbed with an antiseptic and allowed to dry for a few seconds. During the period of treatment, the milk is not fit for human consumption hence the milk is utilized to feed calves or discarded.
The primary contributing factor that determines the recovery of a cow from mastitis is the completeness of milk removal from the infected udder. The injection of oxytocin stimulates efficient milk let down between the particular milking times. The removal of the milk enhances the recovery from mastitis.
Some dairy cows are unable to recover from the mastitis despite antibiotic treatment and frequent stripping of the milk. The cows if not eliminated from the herd they remain a constant source of infection to other cows. In such cases, the farmer is only left with the option of culling the cows with non-responding cases.
Prevention of mastitis
- After each milking, a farmer is advised to dip the teats in disinfectant to kill any bacteria
- At the end of each lactation, the cow should be treated with dry cow antibiotics
- Cows with the mastitis disease should be milked last
- Separate milking equipment should be utilised for the sick cows
- Clipping of the udders to prevent manure from clinging to the teats
- Individual cloth towels should be used to clean and dry the glands
- Farmers milking the cows should always wear clean their hands thoroughly while handling the cow’s teats and udders
- The farmer should strive to minimize teat lesions from mechanical injury
- The milking parlor should be kept clean to avoid environment to cow transmission of mastitis
- The farmer should maintain the cows standing after milking by giving them feed to allow closure of the milk canal