How to identify, prevent and control the mastitis menace!
Mastitis is one of the most common and costly diseases of dairy cattle and can be of significance in beef herds too. As well as causing heavy production losses, mastitis is a significant cause of culling, and in severe, acute cases can quickly lead to death.
Mastitis literally means inflammation of the udder (also known as the mammary glands). This inflammation can be caused by bacteria, which travel up the teat canal, colonize and multiply, leading to damage of the udder tissue.
Types of mastitis
Clinical mastitis is an inflammatory response to infection, characterized by visible abnormalities in the milk or the udder. Sub clinical mastitis is inflammation of the mammary gland that does not create visible changes in the milk or the udder and requires special diagnostic tests for detection. Monitoring and detection of both are key components of a herd health plan.
Mastitis organisms responsible for the infection can be classified as either contagious or environmental, depending on the origin of the pathogen.
Contagious bacteria are spread from a cow with an infected udder to a healthy cow. Transfer of pathogenic bacteria between cows usually occurs at milking time. The main culprits are Streptococcus agalactiae, Staphylococcus aureus and Mycoplasma species.
Environmental bacteria come from the cow’s environment (bedding, soil, manure, etc.) and consequently are highly influenced by management practices. They are ever present where the animals live, and can be controlled by improving cleanliness of cows, their surroundings and the route which they have to take to get to the parlour.
The disease is often a result of fecal contamination e.g by E. coli. Other ‘true’ environmental causes of mastitis include Pseudomonas, Klebsiella and Streptococcus uberis which can also behave as contagious pathogen.
Factors that predispose to Mastitis
- Most important predisposing factor increasing the chance of mastitis is poor hygienic management. The presence of more bacteria around the area is the higher the chance of infection.
- Cattle with a high milk yield will develop mastitis more easily. Their udder tissue is more active and has longer milking time. This makes the teat canal open for a longer period of time. High milk production is also connected with more energy demand which possibly decreases resistance against infections.
- Poor milking technique: Force milking can cause injury to the teat and teat canal making the entrance of bacteria to the udder easier. Incomplete milking is another factor for multiplication of bacteria.
- Unhygienic milking procedure: lack of cleaning utensils, hand of the milker’s and the udder.
- Unhygienic housing system: Just after milking it takes about 20 minutes before the teat canal is fully closed so lack of clean floor and resting places increases the chance of getting mastitis.
- Teat injuries and teat sores: This could be due to different factors which lead to wound formation on the teat.
- Exposure to environmental pathogens: Contamination of the environment where the dairy cattle lives by pathogenic bacteria which would enter the teat and cause mastitis.
Clinical signs of mastitis
Depending on the severity and stage of infection there are:
- Per acute mastitis: There is swelling, heat, pain, and abnormal secretion in the gland, accompanied by fever and other signs of systemic disturbance like depression, weakness, complete loss of appetite.
- Acute / sub acute mastitis: Similar to per acute mastitis but the fever, loss of appetite, depression, systemic change and changes in the gland are slight to moderate.
- Subclinical mastitis: The inflammatory reaction is detectable only through tests, the milk will not change visibly, but taste of milk will become salty.
- The most clear and often first sign of mastitis is characterized by the changes in the milk such as there can be flakes and lumps in the milk, color change of milk, the milk can become watery, instead of creamy yellow or blueish, milk can contain blood clots and looks pink.
Mastitis Detection Techniques
Strip cup technique
The strip cup has a black enameled plate and a cup. Milk the first three spades of milk from each quarter on the plate and checks for lumps, flakes and cloths. After testing store the milk in the cup and dispose in a proper hygienic way.
California Mastitis Test (CMT)
CMT is used to measure the status of udder for subclinical mastitis. It measures the amount of dead cells in the milk. There are always dead cells in the milk due to natural continuous renewal process in milk producing and other udder tissue. Under this condition the amount of dead cells are low and stay under 100,000 cells per millilitre of milk which is undetected by CMT. When there is a subclinical infection, the number of cells increases over 250,000 cells per millilitre of milk and changes will be detected with CMT.
Mastitis prevention and control measures
Step 1: Check the milk equipment
The milk equipment should be clean and dry. Buckets are preferably stored upside in the sun, so the inside will be dry and doesn’t give a suitable climate for bacterial multiplication.
Step 2: Clean the barn
The cleaner the barn is, the fewer bacteria will be present. Avoid wet barn and keep clean and dry to reduce favourable condition for bacteria.
Step 3: Wash and dry your hands
Most of the time hand of a milker is in touch with all kinds of objects contaminated with bacteria. So Proper washing and keeping dry their hands always is important to decrease bacterial contamination.
Wash and keep dry the skin around the udder and teats before starting milking. This is important to remove contaminating microorganisms. When the cow is visibly clean, a dry paper towel will be sufficient.
Step 4: Check the first milk
Use a strip cup and observe if the cow has mastitis infection or not.
Step 5: Milk the udder empty
A good milking technique is crucial for the health of the teat. Complete milking has to be done gently not to injure the teats. Another important technique is a ‘full hand’ milking.
Step 6: Dipping the teat
By applying disinfectant to the teat after milking, bacteria can be removed while the teat canal is still open. This can be done commonly by dipping with an iodine solution in a dip cup as soon as possible after milking. This protects the teats from bacteria to enter the teat canal.
Step 7: Keep the cow standing
It takes a few minutes for the teat canal to close properly. When a cow would lie down in this period on dirty floor bacteria will have the chance to enter the teat canal. Keeping cattle standing, for instance by offering them fresh feed, can reduce the risk mastitis infection.
Step 8: Clean the milking equipment
Cleaning the milking equipment is also important reduce the bacterial contamination. Good cleaning consists of several aspects:
- First removal of dirt by brushing. The better and longer brushed the more dirt will be removed.
- Using detergents with hot water will help to dissolve the dirt.
- Removed detergent by rinsing with clean water.
- Treat milking utensils with disinfectants preferably chlorine solution.
- Then the utensils should be rinsed again dried by putting them upside down in the sun.
Note:- Bacteria cannot be killed by detergents; so disinfection is done only by disinfecting chemicals.
Steps to be followed during treatment of mastitis
1st step: Complete milking of affected cow
By milking the cow as often as possible, preferably every two hours; at least three times a day bacteria and dead cells are removed from the udder. This method is the best and very important to rinse away the infection.
2nd step: Disinfecting the teats
After milking the mastitis affected cows, their teats should be clean and disinfect with disinfectants like alcohol.
3rd step: Application of appropriate the drugs
Direct intramammary infusion of the special antibiotic tubes prepared for the treatment of mastitis twice a day for three consecutive days.
- In case of systemic infection consult veterinarian for additional treatments like antibiotic injection or anti-inflammatory drugs to stop inflammation and reduce the pain.
- Read the manufacturers leaflets for veterinary drugs to be used in dairy cattle concerning withdrawal periods for human consumption.