Cluster Flush

Automated cluster-flushing systems

Various systems have been available for some time that automatically flush-out the cluster unit and/or teatcup liners immediately after each and every cow has been milked. Although their designs vary to a degree, the basic principle behind the concept is that a plumbed-in system using compressed air forces water or sanitised water containing a peracetic acid disinfectant into the cluster or teatcup liner - after the cluster unit has been removed by the Automatic Cluster Remover (ACR) - which is then dried by a further blast of compressed air. Some systems force sanitised water through the long milk tube; others through the short milk tube.

A further addition to the concept in the form of a system which combines automatic teat dipping followed by liner flushing uses a specially-designed teatcup and liner with a small hole at the mouthpiece, and extra pipework adjacent to the pulsation tubes. After milking is completed and the vacuum removed - but before the ACR removes the cluster - a squirt of post-milking teat disinfectant is released into the liner via the small hole at the mouthpiece. The action of the ACR removing the cluster helps to wipe the dip over the teat towards its base and in doing so covers the inside of the liner with disinfectant. Then a series of flushing and compressed-air drying cycles begins, removing both milk and disinfectant residues from the liner. Although this system effectively automates two distinct processes - teat dipping and cluster flushing - by releasing disinfectant solely into the liner, it may not be as effective at flushing as the more established systems which dispense sanitised water into the long or short milk tubes.

The primary advantage of these systems, like any form of post-milking cluster or liner disinfection is that any milk residues which may contain mastitis-causing pathogens from infected cows or contaminated teats are washed from the cluster unit before the opportunity occurs for them to infect the next cow to be milked.

Automatic systems like these are not inexpensive to install - particularly the combined dipping and flushing equipment - but the obvious advantage with such an automated labour-saving system is that effective disinfection of each cluster unit post-milking does not make the milking process significantly longer. The process timings vary from system-to-system but the flushing cycle generally lasts around 30 seconds.

In order to work effectively, these systems require accurate setting-up and maintenance, as the timings between the various processes and the dilutions and amounts of liquid dispensed are crucial to their effectiveness. Where automated flushing is combined with dipping, there is effectively some compromise over dip chemical formulation; post-milking dip chemicals ideally have a long-lasting formulation whereas those designed to be applied and removed within a matter of seconds require rapid kill characteristics.