Source: Upper Austria Chamber of Agriculture
Disinfection of milking clusters is an effective measure to reduce the transmission of cow-associated pathogens and improve the udder health of the herd.
The most important representatives of the group of cow-associated pathogens are Staphylococcus aureus, CNS, and Streptococcus agalactiae, which are transmitted during the milking process. Cows whose elevated cell count is not externally apparent are usually responsible for the excretion and thus the spread of these pathogens in the herd. By reducing the risk of infection and breaking the chain of infection, intermediate disinfection of milking clusters offers a decisive advantage in milking hygiene.
Consistent disinfection of the milking equipment after each cow prevents the spread of Staphylococcus aureus in the herd.
© LK NÖ/Franz Groissmayer
What is meant by intermediate milking cluster disinfection
Depending on the size of the farm and milking parlor, milking clusters are transferred from udder to udder several times without intermediate cleaning. Milk residues in the milking cluster can easily transmit mastitis pathogens from infected to healthy cows. If a milking sequence cannot be maintained, where animals with high cell counts are milked last, intermediate disinfection of the milking clusters can provide a solution. Correct intermediate disinfection of the milking clusters significantly reduces the transmission of cow-associated pathogens during the milking process and the risk of mastitis. Peracetic acid has emerged as a suitable disinfectant. This is an organic acid that decomposes into active oxygen, water, and a weak acetic acid upon contact with oxygen and milk proteins. Peracetic acid products therefore leave no toxic residues and are approved for use in the food industry.
Dilution and shelf life
Products with a pure peracetic acid content of between 5% and 40% are available on the market. When transporting these products, the regulations of the Dangerous Goods Ordinance must be observed. The acid must be stored according to the manufacturer's instructions, but above all in a cool, dry place. The peracetic acid is diluted with cold water; the final concentration should have a peracetic acid content of 800 to 1,000 ppm. With a 40% peracetic acid content in the product, this corresponds to a dilution of 2.5 to 3 ml of acid in one liter of water. The final concentration can be checked using indicator strips. When diluting the products, the manufacturer's instructions must always be followed. Undiluted peracetic acid is highly corrosive, therefore protective goggles and gloves should be worn when handling it. It is important that the working solution is freshly prepared at least once a day, and ideally at each milking time. Otherwise, the working solution loses its effectiveness as the starting materials degrade.
Practical tips for implementation
For all variants, the solution must be allowed to work for at least 30 seconds before the milking cluster is used again.
- Using a spray bottle: This is the simplest method of intermediate disinfection. With this system, the disinfectant solution is sprayed into the teat cups using a spray bottle. Care must be taken to ensure that the teat cup liner surfaces are thoroughly coated with the solution, using at least two to three pumps per cup.
- Immersion method: Here, the milking cluster is immersed in a bucket or tub. This method requires rapid work, as organic components such as milk and feces accelerate the degradation of peracetic acid. It should also be noted that peracetic acid has a corrosive effect on base and non-ferrous metals. If this method is used, it is best to purchase a disinfectant product containing a buffer solution.
- Back-flush or airwash systems: These are automated variants of intermediate disinfection that are particularly suitable for large companies. Disinfection is carried out automatically using disinfectant solution, water, and compressed air.