by Katie Navarra
Mastitis is the most common and most costly disease in milking cattle. It is estimated that mastitis accounts for $1 billion in production losses for the dairy industry each year. The disease challenges conventional and organic dairies alike and prevention is the key to limiting its presence in your herd.
By definition, mastitis is the inflammation of the udder caused by bacterial infection. Mastitis can be subclinical, clinical or chronic. Subclinical is the most difficult to diagnose as no visible signs are present. The udders look normal as does the milk.
While the cow may “look” healthy, if the cow has subclinical mastitis, the somatic cell count will be increased, lowering the overall milk quality. Conversely, cows with clinical mastitis have noticeable changes in the milk as well as swollen udders that are hot to the touch. Cows repeatedly infected are considered chronic.
Because mastitis is caused by the presence of bacteria, “the development of mastitis is proportional to the number of bacteria growing on the teat end,” veterinarian Guy Jodarski said in the webinar Mastitis Management on Your Organic Dairy, hosted by eOrganic. Keeping cows clean, their living conditions and the milking equipment clean is critical in preventing infection.
Attention to detail and understanding how the “mastitis triangle” impacts the spread of mastitis is essential in controlling the disease.
How do I know a cow has mastitis?
In severe cases changes to the udder will be obvious. In cows with subclinical mastitis using one of two tests prior to milking will provide clues. A strip cup is one option. The first stream of milk is squirted into the cup so that the milk can be inspected for flakes, lumps and other abnormalities. This inexpensive test can alert the herdsman to an infection prior to milking before its milk is added to the bulk tank.
Another alternative is the California Mastitis Test (CMT), which Jodarski recommends. “You put milk into a well and add a reagent that shows bacteria,” he explained. There are four wells, one for each quarter. A squirt or two of milk is added to each well along with the reagent.
The mixture is swirled in a circular motion and the presence of gel or slime is recorded for each quarter. A CMT score is used to determine the likelihood of infection. A score of “3” is three times more likely to be positive than a score of “1.” However, it is important to remember that the CMT is not a perfect indicator, but is considered 60-80 percent accurate.
How do I prevent mastitis?
“In a small herd it only takes one or two cows to bump up the somatic cell count in a bulk tank,” he said, “clean cows are important.” Prevention also relies on understanding how the “mastitis triangle” impacts the spread/containment of mastitis.
The people handling the cows during milking must take precautions including hand-washing, wearing milker’s gloves and pre/post dipping.
“During milking time, udder preparation and clean hands/equipment is critical,” he emphasized. Pre-dipping is 40-50 percent effective in keeping bacteria out of the teat end. Post-dipping removes the milk film off the teat and cuts down on the total number of bacteria present. “In organic dairies, there are a lot of iodine dips that are allowed,” he explained, “check with the certifiers to confirm your dip is okay.”
Milking order is also critical to limiting the milk from infected cows in the bulk tank. Jodarski suggested using leg bands to identify infected cows so their milk is diverted from the bulk tank and/or milking those cows last.
The milking equipment is equally important. Milking equipment requires regular maintenance and cleaning to limit the spread of bacteria from one cow to the next. Performance checks, including the vacuum level and pulsation, should be done when the system is not in use (static) and when it is in use (dynamic) to be certain it is working properly.
A cow’s surrounding environment also plays a role in the animal’s substitutability to mastitis. Good nutrition, which includes a balanced diet, trace minerals and vitamins contribute to keeping a cow healthy and allowing the cow to naturally fight off an infection from bacteria. Cows suffering from chronic mastitis should be checked for Electromagnetic Field Stress (EMS), caused by stray voltage to eliminate that as a potential cause.
How do I treat for mastitis?
“Ultimately it is the immune system that eliminates infection, not antibiotics,” reminded Jodarksi. Keeping the cow clean and healthy will go a long way in preventing and treating a cow that becomes infected. That being said, an infected cow must be treated immediately. Organic producers have a variety of options including:
• vitamins and minerals
• allowed synthetics such as conventional fluids, aspirin, etc.
• biologics such as antisera, cell extracts
• topicals including essential oils
• whey products made from colostrum to boost immunity
• herbs/plants such as aloe vera, garlic and tinctures
Jodarski stressed that there is no “silver bullet” or one cure all. Rather, organic producers tend to find a combination of two to three products that they like and that work well in their operation. Above all, “No mastitic milk should be put in the bulk tank for 48-72 hours,” he said. As soon as there are obvious changes or that the cow is not feeling well, take action.
Chronically infected cows that do not respond to treatment should be culled from the herd. It may be difficult to cull cows from the herd, but consider running them like a beef herd and turn them out with calves. This keeps poor quality milk from the bulk tank and it is an excellent way to raise calves. “This is especially good for first calf heifers that can come back the next time without a problem.” This approach does not always work, but is one potential option.
“Prevention (health promotion) should be the main focus of our efforts,” Jodarski concluded, “prevention and treatment involves attention to detail and constant effort.”
by Katie Navarra