Mastitis levels in herds are higher than predicted

The incidence of clinical mastitis in the UK dairy herd is estimated to be considerably higher than past research has indicated, according to a recent report published in Vet Record.

In the last decade, the mean incidence of clinical mastitis has been cited as being between 17 and 43 cases per 100 cows a year. However, according to this nationwide set of results, a more pragmatic estimate appears to be far higher, at between 47 and 65 cases per 100 cows a year, explains lead author of the report Andrew Bradley.

“Following application of the five-point plan, significant progress was made in reducing incidence of clinical mastitis between the 1960s and 1980s. In the 1970s cases were as common as one for every 2500 litres of milk produced. This is now one case for every 10,000 litres,” explains Dr Bradley. “But in the past 20 years there has been little improvement in these ratios.

“Although we have to be careful not to over-hype these results, dairy producers should be aware of the true incidence of mastitis on a national scale,” he believes.


“There have been limited recent data available detailing the national incidence of mastitis, or indeed the pathogens associated with clinical mastitis. The aim was to estimate the true level of mastitis, using a random selection of dairy herds in England and Wales, and to identify pathogens associated with both clinical and subclinical mastitis,” explains Dr Bradley.

Suberis and E-coli were found to be the predominant pathogens isolated from clinical mastitis cases and S uberis from subclinical cases, confirming the prominence of environmental pathogens.

Both environmental pathogens remained the principal causes of clinical and subclinical mastitis during both grazing and winter housing periods, suggesting cases of clinical mastitis may not simply be a result of poor environmental hygiene in winter housing period.

There is a need for more research into the epidemiological features and possible control measures, considering about 25% of clinical cases were recorded as a recurrence in a quarter for that particular lactation, indicating treatment success has the potential to be improved markedly, he believes.


A second Vet Record paper, shows the results of using this research to develop a complete mastitis diagnosis and control plan (MDC Plan). “Results have indicated that it is possible to make a reduction of about 20% in cases of both clinical mastitis and somatic cell counts within a year.”

MDC, sponsors of the research, are currently using this information to compile a comprehensive tool to drive down cases of clinical mastitis. “While farmers will want to put this research to immediate use, there is a need to have a comprehensive set of scientifically proven control measures to allow producers to target mastitis on all levels,” explains MDC’s Philippa Stagg.

Obtaining national data is useful in getting a true picture of the incidence of mastitis in the industry, reckons Devon-based vet Andy Biggs. “It is worth baring in mind these results represent an average, covering a cross section of the industry,” he adds.

“Research like this, and particularly the development of a holistic management plan, will help farmers target action to give the highest economic return. It is essential to identify which control measures will have best effect on individual farms and construct a relevant hit list to combat the top priority factors,” says Mr Biggs.

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