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Mastitis Control Plan Case Study

Published 24 August 09

When Somerset dairy farmer Rob Ham agreed to take part in the research for the DairyCo Mastitis Control Plan back in 2004, he had no great expectations of what could be achieved. He knew the project at that time was in its early stages; that it was as much about collecting national mastitis data as it was about finding a cure; and above all, he knew there was no 'silver bullet'.

"But we weren't hitting that magic bonus button all of the time," says Mr Ham, whose bulk SCC was anything up to around 260,000 cells/ml. "We reckon this was costing us around £5,000 a year in lost bonus payments, so we clearly wanted to address the issue."

In fact it transpired that with the herd's mastitis incidence also running too high - at around 80 to 90 cow cases per 100 cows per year - the savings that could be made were nearer three times the lost bonus figure. And with ongoing attention, such savings have not only been achieved, but have the realistic prospect of rising still further. The process of addressing the problem began when vet, James Breen - one of four mastitis experts charged by DairyCo with devising the plan - visited Mr Ham's 9,100 litre herd of 230 milkers on his farm in Alston Sutton, near Axbridge, when the project was still in its research phase.

"The first and arguably the most important step for each farm is analysing the data from milk records and making a diagnosis," says Dr Breen, who describes the three-pronged approach now recommended as more of a process than a plan. "For this, you are looking at case rates of clinical mastitis; you're looking at somatic cell count patterns, which give an indication of sub-clinical mastitis; and then you are looking at bacteriology - in other words, growing the bugs to identify what they are. "Putting this together allows you to make a diagnosis at the herd level, and gives you an idea of where the disease is coming from.

The herd is then categorised into one of four groups - those with a problem predominantly caused by bugs exhibiting 'contagious behaviour' (typical amongst which is Staph aureus); those with problems caused by pathogens from the environment (eg E coli); those with problems originating in dry cows; and those whose problems originate during lactation.

"Of course, the line gets very blurred," says Dr Breen. "Some herds are outstandingly one way or the other - dry or lactation origin - but a lot are both and you have to judge which is more important. "You don't want to overwhelm people by trying to tackle too much, and on Rob's farm, when we first came here five years ago, you could have made a case for either, but we decided to start with the dry period origin infections, which accounted for more than a third of the clinical mastitis in the herd."

Having analysed the data and made the diagnosis, the next stage (stage two) of the plan is to complete the questionnaire. "The questionnaire usually takes about an hour to complete and is undertaken by the vet or consultant who has been trained in the plan," says Dr Breen, who - together with his three colleagues - is currently in the process of training vets and consultants to roll the plan out across the country.

Split into 12 sections, the questions are exhaustive, and some are answered directly by the farmer and others by the vet or consultant's own observations as he looks over the farm. "There are 381 bits of information we are going to get from the farm by either asking or seeing," says Dr Breen. "We might then reduce that down to 50 pieces of information that the diagnosis suggests are important, and clinical judgement - as well as the software developed for the plan - will both come into play in reducing these further, ideally to no more than 10-12 final recommendations."

A report will then be produced for the farm which will identify measures to address. "These are expressed in a hierarchy," explains Dr Breen. "Some things 'must', some things 'should' and some things 'could' be done, and they are colour coded in red, orange and yellow respectively to indicate their relative importance.

"In Rob's case, because the mastitis was predominantly of dry origin and caused by environmental pathogens, dry cow management became the main focus of attention."

"The approach we had to take was very holistic," recalls Mr Ham. "We had to look at dry cow management as a whole. There was no single most important measure but a lot of small changes were made at the same time."

Bedding became an important issue and was addressed in both the dry cow housing and the calving pens. "Our stocking density was a bit high at the time so the way round this problem was to be more generous with straw and to more frequently clean the pens," he says.  "Then there was the combination therapy at drying off," he continues. "Our administration of dry cow antibiotics and teat sealant had to become more hygienic and now involves a surgical spirit swab and more time and attention.

"We had been drying off at the same time as foot trimming," he admits. "But that was a dirty environment and placed more stress on the cow so now we foot-trim the cows early in the week and dry them off at the end. "With an internal teat sealant, cleanliness is next to godliness, and we learnt by our mistakes."

"The cows are now put back through the parlour after milking - quietly and in a stress-free environment - and the dry cow therapy is administered. That's the gold standard," says Dr Breen. Further nutritional changes were also made including an increase in selenium and vitamin E levels, in consultation with the farm's nutritionist, to boost immune function. Today, mastitis cases have declined to 50-60 cases per 100 cows/year and cell counts - which had dipped to 150,000 - are running at around 180,000.

"Monitoring is the third step in the process," says Dr Breen. "There's no point in making a diagnosis if you don't then watch what is happening or aren't prepared to change. It's all about keeping things on an even keel, and even the best herds find it hard to stay that way.

"In this herd, good progress was made in the dry cow management, but things change over time and now - although there is still an environmental reservoir - the lactation period has become more important." Undertaking a new questionnaire five years after he first came to the farm, he attempts to assess where the new priorities should lie. Some of the issues to be addressed lie in more obvious areas - such as milking routine; parlour disinfection; and separating high cell count or clinically infected cows to be milked after the rest of the herd. For others, the link with mastitis is more difficult to perceive - such as grazing management; poaching; condition scoring; ventilation; or even the use of a dog to move the milking herd.

"That's the trouble with too many investigations," says Dr Breen. "There are myriad reasons behind the disease and at least 150 pathogens that could be involved, but too often the investigation involves a generic approach rather than what makes this herd different."