Editor’s note: Sixth in a mastitis series.

Many factors can contribute to mastitis on the dairy from the environment to the cleanliness of the cows. One area that also impacts mastitis levels is milking equipment, whether it’s improperly functioning equipment or it’s improperly used by milkers.

Mastitis triangle

Before you walk into the parlor and attempt to solve all of the dairy’s problems by placing the blame on equipment or milkers, Andy Johnson, DVM, Seymour, Wis., says you must first look at the whole picture of the dairy. “If you go onto a dairy just looking at equipment as the source of a problem, you may miss that the problem could be a combination of equipment and milking procedures or equipment and environmental problems, for example.”

Johnson says a mastitis investigation should encompass the “mastitis triangle.” “We always look at three things: man and his milking procedures, cows and their environment and the milking equipment,” he says. “No matter what your pre-conceived notion is of the problem, every farm I go to I look at these three areas. If you don’t, you might find one thing to fix, but your overall problem does not go away.”

Hank Spencer, DVM, Aubrey, Texas, agrees and says that to prevent mastitis, we must reduce the bacterial load on the cow’s teat and then prevent the bacteria from getting into the cows udder. “Though we can’t have a totally sterile teat, reducing the bacteria load begins with proper maintenance of the environment, proper use of wash pens, the use of pre-dips and post-dips that are proven and effective, as well as proper milking technique. The milking equipment can act as a fomite to transmit bacteria from cow to cow, and preventing bacteria from getting into the cow’s udder is a critical function of the milking equipment.”

Spencer adds that excessive reverse pressure gradients or vacuum fluctuations at the teat end, improper pulsation, over- or under-milking, as well as teat end lesions, tend to be linked to improperly functioning milking equipment and will lead to mastitis problems.

Mark Wustenberg, DVM, Kilchis Dairy Herd Services, Bay City, Ore., says the milking machine can be a major factor in introducing bacteria back into the teat. “Under-milking may contribute to higher SCCs in already infected cows. Over-milking and inappropriate vacuum settings and poor massage characteristics may contribute to problems with teat end health such as increased callousing.”

Investigating a problem

Investigating a mastitis problem encompasses the three areas of environment, equipment and technique. If you believe the problem is in the equipment, Johnson says you don’t necessarily need fancy tools to find out – start by looking at the teats when the units come off. Check to see if they are normal, soft, red, sore or hard.

Johnson has a treatment log used for every cow that is clinical, and on that log teat condition is noted. “I’ve found that on many of these dairies, 8 out of 10 of their clinical cases will have poor teat ends. These are things we can do without measuring and just using good observation.”

Other indicators can be an increase in clinical mastitis cases. Somatic cell counts may not always be a good indicator, even if you have a major problem, if cows are being pulled from the string which makes the bulk tank SCCs relatively low. Johnson likes to have bulk tank cultures prior to his visit if possible, to get an idea of whether the mastitis problem is contagious or environmental.

Wustenberg says he tends to group clinicals or cows with SCC problems into three areas: fresh cows, newly-infected cows and chronic cows. “If the problem seems to involve more fresh cows than the other two groups, it is probably not a problem with milkers and/or machines,” he says. “In the other two groups the machine may be involved, but you have to remember that machine, milkers and the environment all come together at the udder and usually there is more than one factor involved.”

Wustenberg uses the NMC recommendations when investigating problems and feels strongly that you have to spend time watching cows milk to really know how a machine is performing.

Spencer concurs and says after ruling out environmental factors and milking techniques, veterinarians should first run through the National Mastitis Council recommendations on evaluating vacuum levels and air flow in milking systems when investigating an equipment problem.

Common equipment problems

Probably the most common problem with milking equipment is maintenance. Spencer says milking machine companies have quality products that mostly meet or exceed National Mastitis Council and ASAE guidelines. “Unfortunately, once the equipment is in place, the maintenance often is less than satisfactory,” he says. “Rubber goods are not replaced on a regular basis. Regulators and pulsators are checked only when problems arise. Preventive maintenance on the part of the producer would help tremendously in preventing mastitis outbreaks.”

Wustenberg adds that many of the things that revolve around maintenance don’t require fancy equipment. “They require a knowledge of what needs to be done, plus training and monitoring. This is an area veterinarians can be involved in. I don’t have to do the actual machine exams to know whether the machine is working correctly as long as the person in charge of this area is doing his job and we have some sort of verification system. I will have that person leave his analysis sheets for me to look at, for example.”

He adds that many machines are designed and installed correctly but they aren’t maintained well, and many times they have not been fine-tuned to optimize the machine/cow interaction. “There is usually significant opportunity to improve the operation simply by teaching milkers and those associated with the parlor, proper milking techniques as well as routine maintenance procedure.”

Other problems include things like improper location of the regulator which will significantly affect its performance. Most companies have detailed instructions on how to position and plumb a regulator, notes Spencer, but, “unfortunately, owner’s manuals are often ignored.” He says dairies must have enough effective reserve to cover worst case scenarios such as adding milkers due to environmental conditions, changes in milking technique or switching, for example, from a 5/8" claw to a 7/8" claw.

Improper take-off settings can also cause problems if they are not adjusted to allow complete milkout. “This will be dependent on vacuum levels, liner characteristics and herd production,” says Spencer. “There is no one-size-fits-all.”

“For years the industry has said high vacuum causes problems, but actually what we’re seeing is low vacuum causing problems, and trying to get too much milk out of the cow,” adds Johnson. He’s involved in studies that show high-producing cows can go from a 7.5-minute milking time to under 4.5 minutes without any compromise in quality or components.

He recommends doing some quick strip-yields on a few cows after the milking units have detached to see how much milk is left in the udder. He uses a plastic measuring cup and says the goal is to have under 250 ml of milk left, but dairies that are consistently at 50 ml are milking the cows too dry and that puts too much stress on the udders.

Throughput is also important, but Wustenberg says it’s common for dairies to ignore the true cost of pushing higher cow flows. “Many times we sacrifice milking clean, dry udders for just getting more cows through.” Even when cow flow is not a big issue, he says extended claw times and over-milking may not be good. “There is probably a reason to look at poor cow flow even if we are getting everyone milked with the current system.”

Spencer adds that parlor throughput is not about how fast you can attach a unit, but how fast you can harvest your product. “Often with a little easier manner in handling the cows and a proper milking technique, parlor throughput will increase.”

Milker problems

“The most common thing we see at milking time is if the milkers have poor preparation, the cows have poor letdown, causing problems like the cow taking 45 seconds once the unit’s attached to start the milk flow,” says Johnson. “Or, we’ll have the cow with instant letdown and 30 seconds later there will be no milk flow. You need to see if the milkers are using automatic or manual settings. Often it’s not the equipment, but how the cows are prepped.” He says veterinarians can easily do a recovery time test on the milking system to get an idea of the airflow and see if the regulator is working correctly. “If you have a lousy recovery time, you can have some serious problems.”

Spencer says poor unit alignment is the number one problem he sees on dairies. Often it’s due to not supplying labor with the proper equipment, as well as poor milker training. He says unit alignment can have a dramatic impact on how the cow milks out, but it is often ignored.

Not using automation is also a problem. “Management has spent a lot of money in automation that is not getting used,” says Spencer. “Some of the time it’s maintenance of the equipment, but often it’s a decision on the part of labor. If clients are going to invest in automation, they need to maintain it, set it properly and use it. If they are not going to use it properly, it should be removed.”

And though not part of equipment, per se, Spencer says a breakdown in the basic post-dipping procedure can add tremendously to a contagious mastitis problem. Wustenberg adds that training employees on proper milking techniques is often the best opportunity for the veterinarian to become initially involved in the entire udder health program.

There is an increasing number of veterinarians becoming interested in working more with milking machines, says Wustenberg. “As part of a management team involved in udder health management, I think it’s extremely important to know about the machine even if you’re not the one directly doing the work. Many times I recognize problems during my milking time evaluations that the dealer didn’t catch because he is only working on the machine when there are no cows being milked.”

Veterinarians must take a proactive role in observing and establishing proper milking techniques, says Spencer. “Milking technique and labor management is a critical leg of the mastitis triad.”