Automatic cluster disinfection can cut mastitis levels

Automatic cluster disinfection systems can be instrumental in mastitis control. Debbie James speaks to two farmers who have seen such benefits.

Mastitis is one of the most significant health problems in UK dairy herds, estimated to cost between £69-£228 a cow a year.

The bacteria that cause mastitis can come either from a cow’s environment or it can be spread from cow to cow, usually from the udder and teat lesions.

Both environmental and contagious mastitis can quickly infect a herd, but a number of techniques, from good parlour hygiene to the more expensive cluster disinfection, can halt the spread of pathogens.

Robert Davies installed an automated cluster disinfection system in his parlour to tackle sub-clinical mastitis. At its worst, his herd’s cell reading had rocketed to 500,000cells/100ml and was costing him 2.5p/litre in lost income.

Before installing a cluster flush system, he had implemented several measures to bring the cell count level down – pre-dipping teats, dipping the clusters, spraying the cubicles and separating high cell-count cows from the rest of the herd. He also tested the herd monthly and culled infected cows. But none of these worked.

He then invested £11,500 in a cluster disinfection system and changed the clusters in his 20/20 direct line parlour for lighter models. He believes the system paid for itself within six months. His cell count readings quickly dropped to 250,000 cells/100ml.

Backflush prevents mastitis spreading from udder to udder by flushing the clusters and milk tubes with air after each individual milking, followed by water and then a flush of chemical solution. Finally, air is blown through the system.

For Aeron and Carys Owens, contagious mastitis was the issue. The herd became infected with the Staph aureus bacteria and within two months their cell count reading had increased from 100,000 to 300,000 cells/100ml.

“The infection could spread from one cow to 12 in a couple of days. We were losing between 0.2p/litre and 0.5p/litre because our cell count was way over the threshold,” says Mrs Owens.

On the advice of their vet they culled some of the older cows – mainly third or fourth calvers that were going to be difficult to cure. They also started dipping the clusters in buckets of chemical solution. This action did help but their cell count still hovered above 200,000 cells/100ml.

They also invested in a cluster disinfection system and saw an immediate improvement.

Their latest cell count result showed 80,000 cells/100ml. The herd is averaging 10,600 litres with 4.37% butterfat and 3.3% protein. “Cow health is phenomenal. We brought 64 heifers into the herd last year but we haven’t had a case of mastitis since Christmas,” says Mrs Owens.

“We installed the system two years ago but it has paid for itself already, not only through the higher milk price we are getting but in labour savings. When we were dipping the clusters by hand, every milking was taking half an hour longer.”

An additional tool in their mastitis management programme is the Californian Milk Test (CMT), which they use to identify problems at an early stage. The test is simple and instant and infected quarters can be quarantined and treated to prevent infection spreading from cluster to cluster.

The advantage of CMT over individual cow cell counts is that it assesses the level of infection of each quarter rather than an overall udder result, says Mrs Owens.

Dairy vet Neil Howie agrees that the risk of mastitis infection can be reduced by focusing on the milking parlour.

He says it is essential that milk let-down is achieved before the unit is applied because anything that affects this process will increase the risk of teat end damage.

“Pre-dipping with either iodine, hypochlorite or chemical wipes will stimulate milk let down, which means the process of harvesting the milk is less likely to harm the cows,” he says.

Milking machine faults and poor milking techniques are probably among the main environmental risk factors for mastitis, alongside housing hygiene, he adds.

“It is vital the cluster hangs squarely under the udder without any pull or tension either side,” he says.

Disinfecting teats before milking prevents the spread of contagious and primarily environmental pathogens during milking, while disinfection post-milking has a major effect on the microbes growing on the teat that may have been spread during milking.

Infected cows should be milked separately or last and udders, teat and the milking machine must be kept clean, says Mr Howie.

Clean, comfortable bedding is essential for housed cows and there should be a rotation of paddocks if cows are calving outdoors. “Pasture can become contaminated when the paddocks are used heavily during calving,” says Mr Howie.

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