PREVENTION & CONTROL OF MASTITIS IN DAIRY FARMS
What is Mastitis?——–
Mastitis is an inflammation of the udder caused by a variety of microbes, mostly bacteria, that gain access to the interior of the mammary gland through the teat canal. These microbes live on the cow, its udder and in its environment, including the floor, faeces, soil, feedstuffs, water, plants, and milking equipment and utensils. In response to these bacterial invasions, cells move from the blood stream into milk in order to fight the infection. Fortunately, these organisms are normally killed by pasteurisation and thus seldom cause disease in humans, unless the equipment is faulty or if raw milk becomes contaminated with these organisms.
There are two major causes of mastitis and they include;
- Infection – Most cases of Mastitis usually occur as a result of a bacterial infection such as Streptococcus agalactiae and Staphylococcus aureus. These bacterial organisms may be transmitted to the cows through bedding or contaminated teat dips. The infection then incites an immune response that will develop to mastitis in the cow
- Injury – Mastitis can also occur as a result of injury to the cow’s udder. The injury may be physical, chemical, mechanical, or thermal.
What are the predisposing factors and risks of a cow having mastitis?——–
It is important to note that generally, mastitis is usually multi-factorial; resulting from factors that may include the farm’s production system, the environment the cows are kept in, level of immunity of the cow and the type of invading pathogen that causes the infection.
Also, flies are a large factor in the spread of the disease most especially if the cows are held in confined areas with high fly populations. Flies carry the disease, moving bacteria from the skin surface into the tissue by biting at the teat ends and exposing live tissue. This is the entry point of the pathogen which allows the bacteria into the udder infects the specific quarter.
Older cows, are at greater risk of getting mastitis because they typically have larger udders than younger cows. Therefore, the chance of physical injury by being stepped on is greater, and in early lactation the udder often contacts the ground, allowing the entry of bacteria into the teats.
Calves can also spread the infection from quarter to quarter when they suckle for milk and they suckle across teats.Also, if cross suckling across cows occurs, bacteria can be spread to other cows
Weather is also a risk factor for mastitis to occur. Higher instances of mastitis can occur when the weather changes from hot and humid, to wet and muddy conditions.
Economic implication of Mastitis————–
Mastitis causes significant economic losses to the farmer as most farmers depend on the milk produced from the udder to care for the calves and also to sell/process into milk and milk products (cheese, wara etc.). So, generally, a cow with mastitis has a lower milk yield, leads to reducing weaning weights of the growing calf and reducing profitability of the animal farm operation. Also, mastitis can reduce fertility (first service conception rates) and delay the onset of heat cycles in cows which also reduces the overall profitability of the farm.
How do you know a cow has clinical mastitis?———-
The most obvious symptoms of clinical mastitis in cows are as follows; Swollen udder, heat, hardness, redness or pain. Also, the infected cow’s milk takes on a watery appearance and flakes, clots or pus is often present. Other common signs include a reduction in milk yields, increases in body temperature, lack of appetite, and a reduction or reluctance to move due to the pain of a swollen udder.
How do you treat mastitis in cows?————
Due to the infectious nature of mastitis, they should typically be treated with antibiotics. Even the mastitis that result from injury should be treated with antibiotics to prevent and resolve any infectious complication of the injury. To treat, the cow can be milked out and then the antibiotic can be infused directly into the infected gland. It is best to contact your veterinarian for the specific antibiotic to use, correct dosage and method of application specially to avoid antibiotic abuse.
Other ways of treatment and resolving mastitis in cows is the administration of oxytocin to stimulate milk let-down and milk flow so as to relieve the udder of bacterial load and growth medium. Also NSAID (non-steroid anti-inflammatory drugs) can be given to reduce the swollen state and pain of the udder.
For mastitis that refuse to heal even after constant and prolonged treatment, it might be best to cull the animal so that the (mastitis) infection does not spread to other cows in the cattle herd.
How can you prevent Mastitis in the cows on your cattle farm?
• By hygienic management of the cow teats which includes good housing management, effective teat preparation and disinfection for good milk hygiene, teat health and disease control.
• By maintaining a healthy habitable environment in your farm. In fact, managing the environment is much more important that using medications. When treating active cases, ensure the treatment area is clean, as more problems can occur with poor sanitation and unhygienic environment. Also, avoid keeping cows in confinement areas as much as possible.
• By prompt identification and treatment of clinical mastitis cases including the use of the most appropriate treatment for the symptoms. You veterinarian would be the best to know about this. For example, if there is a history of mastitis in the herd, heifers they should be treated one month prior to calving
• By culling chronically affected cows; cows whose mastitis infection have refused to heal and might become sources of infection to the rest of the herd.
• By regular and hygienic maintenance of the milking equipment daily, weekly or monthly basis.
• By maintaining good record keeping of all aspects of mastitis treatment and cases so as to monitor incidence of infection, changes, treatment and prevention plans in the cattle herd.
• By ensuring that cows are receiving proper nutrition and clean grass so that they can maintain a proper immune system and would be less prone to infectious micro-organisms causing mastitis
Through everything, ensure you consult your veterinarian for a proper plan on the treatment and prevention of mastitis on your farm. This would save you from economic and financial losses in the long run.
Recommended milking procedures to prevent mastitis in dairy cattle—–
The 15 min each day when cows are milked is a prime time for increased susceptibility to new mastitis infections. Correct milking procedures are important, regardless of whether cows are milked by hand or machines. Preparation of teats and udders for milking reduces the number of contaminating microbes on teat skin, and stimulates milk letdown. As well as reducing this contamination, it decreases residual milk left in the udder at the end of milking, increases milk yield, decreases milking time and reduces the spread of contagious and environmental organisms that cause mastitis and reduce milk quality.
Key milking procedures include the following:
• Provide cows with a clean, stress-free environment. The cows should not be frightened or excited before milking because this stress will release hormones that interfere with normal milk let-down and reduce the cow’s resistance to mastitis.
• When washing the cow or cooling it down, ensure that at least 30 min elapses before milk harvesting, to minimise the likelihood of dirty water dripping off the teats during milking
• Check the udder and foremilk for mastitis. Clinical mastitis can be visually detected from clotty, stringy or watery milk or hot, hard and enlarged quarters.
• Wash the teats and lower surfaces of the udder. Correct washing and massaging releases hormones for milk let-down. A sanitising solution should be used in the bucket with an individual cloth or paper towel to wash the udder. Do not use a common cloth because it allows for cross contamination between cows.
• Use a pre-milking teat dip (optional). Disinfecting teats before milking reduces the rate of infection of environmental mastitis by 50%, as well as reducing contagious mastitis. The recommended procedure is to wait 20–30 seconds after pre-dipping teats, then thoroughly dry the teats prior to applying teat cups.
• Dry the teat thoroughly. Using excess water to wash teats and udders and not drying them properly results in water laden with microbes draining down into the milk bucket (with hand milking) or being drawn into the teat cups of milking machines.
• Hands should never come into direct contact with milk.
• Attach teat cups within 1 min. Attachment must be done carefully to prevent entrance of excessive air into the milking system. Maximum internal udder pressure is reached within 1 min after udder preparation and lasts for about 5 min. Because the majority of cows will milk out in 3–5 min, the 1 min delay in attaching the milk cups maximises the effectiveness of the milk let-down hormone oxytocin.
• Observe milking units closely while attached to ensure that they are adjusted correctly and to aid in preventing cup slip. Slipping or squawking cups slow down the milking operation and may cause machine-induced infections. Liner slip can allow tiny droplets of milk to be quickly propelled against the end of the teat, which may penetrate the teat canal. Because most liner slip occurs towards the end of the milking, the chance of these organisms being flushed out is reduced, leading to an infected quarter.
• Avoid irregular vacuum drops due to sudden air intakes when connecting or removing the milk clusters.
• Shut off the vacuum before removing the teat cups at the end of milking. Never pull the milking unit off the udder while still under vacuum because this causes the same problem as squawking cups, leading to infections (referred to above). A minute or two of over milking with a properly functioning milking unit does not pose a major risk in term of mastitis. If one quarter milks out ahead of the others and if the teat cup remains attached to the teat without slipping, it should be left on because careless removal may permit air to enter, possibly leading to liner slip-induced infection. If there is a probability of cup slip on a particular teat, then the cluster should be lifted gently to seal the short milk tube of the liner over the ferrule of the claw to shut off the vacuum before detaching it from the teat. Never remove a teat cup while under vacuum.
• Don’t over milk any cow; 8 min is maximum milking time, even for a slow milker.
• Dip teats with an effective teat dip. This is the most important way to reduce new infections of environmental mastitis. The goal should be to dip the entire surface of the teat that comes into contact with the teat cup liner. Teat spraying never covers the entire teat surface. Teat cups should be kept clean and sanitary, but teat dip should never be poured back into the original container because the strength of the used teat dip may be reduced and allow organisms to survive.
• Disinfect teat cups between cows (optional). Teat cups can spread organisms from one cow to another. If they are to be disinfected between cows, two teat cups should be dipped at a time in a disinfectant solution. The solution should be changed when it becomes cloudy to ensure mastitis organisms are killed rather than spread
. • When the milking session is complete, clean and disinfect the teat cup liners properly, using hot water plus detergent followed by hot water plus sterilising agents.
• Allow each cluster to drain between milking sessions.
• If using a bucket milking machine, ensure the bucket is hung upside down so it can drain properly before reuse.
• Feed the cows immediately after milking to ensure they do not lie down for at least 30 min.
• Ensure the cows lie down on clean bedding or a clean floor. When milking mastitis-infected cows:
• Draft out clinically affected cows and milk them last.
• Use gloves when milking mastitis-infected cows.
• Rinse and sanitise the milk cluster after milking each mastitis-infected cow and don’t touch any other cluster or cow for at least 20 seconds. To reduce exposure to environmental mastitis:
• Calve cows down in a clean and dry area.
• Be alert to the number of cases of mastitis occurring in freshly calved heifers; this is an indicator of the state of the calving area.
• Bring cows into the dairy for milking out and checking, certainly within 24 hr post-calving.
• Look for swollen quarters and check them for heat and pain.
• Check milk from all quarters of freshly calved cows.
• Take special care of induced cows; that is, cows that have been treated to calve down early.
• Take special care with pre-milking preparation; that is, teat cleanliness and ensuring all milking equipment has been sterilised and allowed to drain.
Recommendations for milking machines—————
Mastitis can result from improper design, malfunctioning, misuse or improper cleaning of milking machines. If they are properly designed, maintained and used, milking machines will account for only 6% of all udder infections. Although they differ in design and size, all milking systems have the same basic components. These include systems to produce a vacuum, pulsation, milk removal and milk handling, which are all run by an electrical system. With respect to mastitis control, it is the milk removal system – in particular the teat cup liner slips – that are associated with milking machine-induced infections. A problem with liner slip exists if there are more than 5–10 liner slips per 100 cows milked. Some of the causes of this include poor cluster alignment, poor liner design, uneven weight distribution clusters, blocked air vents at the claw and flooded milk lines. In addition, cup slip results from inappropriate liner design, cluster weight, vacuum levels, vacuum fluctuations, milking wet teats, absence of hose support arms, over milking and teat size.
The steps in milking machine maintenance include the following:
• Ensure the milking machine technician closely follows the maintenance schedule for testing and servicing the machine.
• Regularly check the pulsation rate of the machine: 60 pulsations/min is the recommendation.
• Regularly check the vacuum pressure and ensure it is not too variable during milking.
• Ensure the diameter of the vacuum line corresponds with the capacity of the vacuum pump.
• Ensure the vacuum line is not too long; that is, the distance between the vacuum pump and the teat cups.
• Routinely replace any cracked milk tubes.
• Replace the milk cluster rubber liners after 2500 milkings, using the following simple formula: Replacement age (days) herd size milkings/day 2500 number of claws # # = Therefore, for a 40 cow farm milking twice daily, with one mobile milking machine with two claws, the rubberware should be replaced every (2500 × 2)/(40 × 2) or every 62 days.
The following treatment protocol for mastitis should be followed by the veterinarian or dairy cooperative animal health staff:
• Regularly monitor each cow for sub-clinical mastitis, preferably using the CMT.
• Apply antibiotics under veterinary supervision, ensuring it is the most appropriate for the mastitis infection.
• Use the full course of antibiotics, as specified on the label.
• Clearly mark treated cows.
• Keep records of treatment to clinically affected quarters.
• Ensure the withholding periods (for drug use) are followed before mixing the milk with that of the rest of the milking herd.
• Discard milk from all quarters of cows that receive treatment.
• If a cow fails to respond to full treatment, consider a repeat course of the same or another antibiotic, drying off the infected quarter, drying off the cow or even culling the cow.
Preventive measures—-
• Cow should be allowed in soft bedding following parturition.
• Concrete floor should be avoided especially in case of high yielder. Bedding should be done with straw, saw dust or sand. Sand is the ideal bedding material since it has lower bacterial count.
• Infusion should be used in each cow at dried off.
• Always the animal sheds should be clean.
• Washing the udder and hand of the milker with antiseptic lotion (4% Pottasium permanganate solution) before and after milking.
• The floor of the milking shed should be washed with running water.
• The milker’s hand should be free from nail.
• Cleaning and disinfecting milking machine and the teat cup, vessels after each milking.
• The healthy non-infected cows should be milked first and known infected cows should be milked at last.
• Newly introduced cow should be milked separately and should be screened through California Mastitis Test (CMT).
• The first strip of milk should not be allowed to fall on the floor; they may be stripped in separate container along with disinfectants in it.
• Dipping of all teats following each milking with iodophor solution containing 1% available iodine or hypochlorite solution and Chlorhexidine in 0.5% to 1% polyvenylpyrrolidine solution.
• Immediately after milking should not allow the animal to lie-down by engaging with fodder.
• The milking timings should be in a regular manner.
• The complete milking should be done at every time and milk should not be stored in teats.
• The udder and teats should be protected from any injuries.
• Hygienic measures at milking time, udder preparation before milking, post milking teat disinfections have been recommended as preventive measures.
• Control of fly population should be attempted, for these insecticides fly repellent sprays are to be made in the house and surroundings.
• The frequently affected animals should be removed from the herd.•
Suggested first aid——-
• Application of ice cubes on the udder surface.
• The milk from infected teat should be milked out daily three times and disposed safely outside.
• Calf should not be allowed to suck the infected teat.
• Antibiotic treatment and consultation should be made with qualified veterinary Doctor.
Control measures—-
• Immediately after detecting clinical signs, it should be consulted with qualified veterinarian for further antibiotic treatment.
• The infected animal should be kept separately from other animals.
• The calf should not be allowed to suck the infected teats.
• The milk from infected teat should be milked out daily three times and disposed properly without contaminate the environment.
• Mastitis milk should be properly disposed. 5% phenol may be added to the infected milk at the time of disposal.
• The healthy non-infected cows should be milked first and known infected cows should be milked at last.
• The non-responsive quarter should be permanently dried up.
MASTITIS MANAGEMENT IN DAIRY ANIMALS CAN BE DOWNLOADED FROM HERE-
http://naas.org.in/Policy%20Papers/policy%2061.pdf
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development)
Image-Courtesy-Google
Reference-On Request.
