One of the highest risk periods for mastitis in a cow’s life is the period just after it is dried off. Bacteria enter the mammary gland when the teat canal is open, and in the period just after dry-off the teat canal can remain open for a while.
This is because the cow is not being milked out two or three times a day, and the udder pressure is quite high. This all leads to the fact that we need to be very careful to minimize the exposure of the teat end to mastitis-causing organisms at the time of dry-off and for the next few days until milk production stops and the teat canal fully seals off.
Having a proper dry-off protocol is something that has been discussed for years, but the reality on many farms is that there can be a lot of variation in this area.
Many times this procedure is done during a short time window and therefore numerous people may be recruited to help. The challenge is: Some of these people may not have been trained in good intramammary treatment technique.
This means that sometimes we actually introduce mastitis-causing organisms at the same time we are using an antibiotic to prevent them. Depending on the amount of organisms introduced and the cow’s immune system, these bacteria can set up shop and start a mastitis infection that now has two months of time to establish itself before calving.
This can mean that by the time the cow calves and is noticed to have a high somatic cell count in one quarter or maybe has a clinical mastitis event, the infection is already deep-seated and chronic. The cure rates on these types of infections are poor.
Dry-off protocols
In order to manage and monitor this critical protocol, some farms are going to the next level. This usually involves the herd veterinarian observing the current dry-off protocol and then writing out a detailed standard operating procedure (SOP) for the entire process.
This SOP is then posted for all employees to see but, more importantly, there is a training session with all employees who will be drying cows off to go over the SOP. This training session is mandatory for any employees who will be drying cows off.
After this is complete, the herd veterinarian or some other outside qualified person observes each employee actually perform the dry-off procedure. Any issues that arise are discussed and corrected and, after both parties are satisfied, the employee receives a written certification to perform dry cow treatment on this dairy.
Only those employees who have been certified in the dry-off protocol are allowed to dry treat cows. After these initial trainings, each employee is observed doing the procedure at least every six months to ensure protocol compliance.
Going through the above process on multiple dairies has brought to light some very interesting results. On one dairy it was determined that all available milking staff helped out on dry-off day due to the need to minimize downtime in the parlor where the procedure was performed.
This meant that milkers who were not trained or allowed to perform lactating cow intramammary treatments were allowed to dry treat cows.
On another dairy with a similar time crunch, it was determined that the farm needed to provide multiple mobile stations with the necessary supplies of alcohol-soaked gauze, additional towels and treatment tubes to minimize the amount of walking time and the risk of contaminating the supplies by placing them in dirty areas.
On a third dairy using an internal teat sealant, it was discovered that the procedure of holding off the teat base while the internal teat sealant was being injected was not being performed. This meant that the internal teat sealant was being dispersed throughout the quarter rather than just remaining in the teat cistern.
When this happens, it can have a downstream effect because, after these cows calve, they can shed the internal teat sealant for multiple days. This product can then accumulate in the milking equipment and cause milk quality issues on the cleaning side. After freshening, the teat sealant should be manually stripped from the teat canal before machine milking.
Proper handling of teat sealants
Any teat sealant not removed from the udder by manual stripping will end up in the milking equipment. How long the sealant remains in the milking equipment is influenced by many factors. Some of the most important factors have to do with how well the milking system washes. These include: water temperatures, detergent balance, turbulence and drainage.
Water temperature is one of the most critical factors for removing teat sealants from the milking system. Like most greases and oils, teat sealants thicken as they get colder. Eventually, they will turn from a semi-liquid state to a solid state. Once they solidify, they no longer flow with the washwater and begin to stick to inside surfaces of the equipment.
Therefore, it is critical that the pre-rinse be kept in the 100 to 120ºF range. The detergent cycle needs to start between 160 and 180ºF and end at no less than 120ºF. Temperatures consistently cooler than these will likely result in problems.
Detergent balance is the next factor to consider. Traditional pipeline detergents are designed to be safe on the milking equipment while dissolving milkfat and milk protein. They are not designed to dissolve the heavier oils found in teat sealants.
Boosting the alkalinity in the detergent can sometimes help prevent sealants from depositing in the equipment. Detergents with greater levels of surfactants can also help. Additional chlorine has not appeared to help and may be detrimental to the rubber components.
Turbulence inside the equipment keeps the sealant particles moving and does not allow them to attach to the inside of the equipment. We often see deposits in low-turbulence areas such as the receivers, batch tanks, meters and claws.
Deposits on the sides of the receivers can be kept at bay through proper air injection. Good air injection will send 20 to 25 good slugs of water into the receiver over an eight- to 10-minute wash.
Batch tanks can be tough to get good turbulence. The sealants can collect at one level during milking. This level may be under the water line during the wash. This prevents the spray ball from providing sheeting action to remove the sealant.
Washwater travels through the milk hoses at a fairly fast rate, but it slows down dramatically as it enters the meters and claws. This decrease in velocity gives the sealant particles the time they need to attach to the milking surfaces. It is critical to ensure that every meter and claw receives as much water as they can without flooding the receiver and trap to maintain water velocity.
Proper drainage is important because it ties into temperature and turbulence. Once the system shuts down, the water begins to cool off and all turbulence stops. If the system takes a long time to drain, it will allow teat sealants to settle onto the milking equipment. Large equipment needs large drains. If you see deposits on the bottom of the receiver, it is likely due to slow drainage.
Another factor that influences the removal of sealants and cleaning in general is the time between the end of milking and the beginning of the wash. The wash should be started as soon as possible after the milking session ends. Performing other tasks before starting the wash allows the sealants to cool and settle onto the equipment.
Once a teat sealant has built up in the milking system, it can be very hard to remove. I recommend the following procedure for removal of teat sealant deposits. First, ensure your system is washing properly, as explained above. Second, manually remove any deposits in the batch tank or receiver.
This is important because some shock treatments may not completely dissolve the teat sealants; they just push it around from one part of the system to another. Next, shock the system. Do not try to shock by adding high amounts of traditional cleaners. They will not remove the deposits. Several companies make commercially available products for removing teat sealants. Use one of these products to shock the system.
Be sure to follow the manufacturer’s recommendation carefully. The solvents and degreasers in these products may not be compatible with your system components. This is especially true of meter parts and gaskets.
Last, manually re-clean the batch tank and receiver, as the shock treatment will likely have deposited more teat sealant to these areas. It may be necessary to repeat the process several times, depending on the severity of the problem.
Dry-off teat sealants have proven to be of benefit for improving milk quality – when managed correctly. Correct management begins with proper cowside procedures at dry-off and freshening, and ends with the wash to prevent the sealants from depositing inside milking equipment.
Paying attention to the details will maximize the benefits derived from these products and minimize the side effects. 
Chris Elliott is an executive account manager with Ecolab Inc. Both serve on the board for the Empire State Milk Quality Council, a not-for-profit organization made up of people from all aspects of the New York state dairy industry.
Paul Virkler is the senior extension associate with Quality Milk Production Services. Email Paul Virkler.
