How fore-milking can increase mastitis detection by 146%

Research conducted on Irish dairy farms showed fore-stripping increased clinical mastitis detection by up to 146%.

The finding led PhD student Rachael Millar to conclude that clinical mastitis may be under-detected. She recommends fore-stripping is used as a regular, routine detection tool, not just at particular times of year.

See also: How changes to ventilation and bedding cut mastitis

Early detection and testing could not only improve cure rates for mastitis, but also reduce the risk of further cases.

“If farmers know there’s a case there, they might be more hygienic in relation to reducing cow-to-cow spread and keeping it out of the bulk tank,” Rachael said.

The research study worked with 80 herds milking conventionally, which broadly represented Irish dairy farms.

Of these, 40 were the control farms that continued standard milking practices, while 40 did a week of fore-stripping three times across the 13-month trial window.

The intervention farms were provided with a strip cup, which aids the visible detection of clots or other abnormalities in the milk.

They were trained on using the cup and collecting an aseptic sample and were asked to strip every cow in the milking herd during the three intervention weeks. Potentially infected milk was frozen, collected and assessed.

Environmental pathogens most prevalent

Streptococcus uberis was the most commonly identified bacteria (19.2%) in the samples, followed by E coli and Staphylococcus aureus.

This was “contrary to the belief that S aureus is the most common pathogen in Ireland” and showed instead that environmental pathogens are the most common, Rachael explained.

“We can suggest from our results that there is an under-reporting of clinical mastitis on our Irish dairy farms and that it may be misrepresenting our true incidence,” Rachael said.

She emphasised the importance of management factors such as disinfection pre-milking or post-milking to manage environmental pathogens.

Mastitis detection higher each week using strip cup

There was an increase in detection during each of the intervention weeks, and it varied seasonally:

• In spring, 31 cases were detected the week before stripping, compared with 36 cases in the intervention week – an increase of 16%
• In summer, 27 cases were detected the week before stripping, compared with 59 cases in the intervention week – a significant increase of 119%
• In winter, 26 cases were detected the week before stripping, compared with 64 cases in the intervention week – an increase of 146%.

Rachael said this shows that stripping cows in springtime alone, perceived as the critical time for detection, is not enough.

“We could also argue that, in summer, there’s the milder, chronic cases that the farmer may be detecting this time of year,” she added.

Rachael shared the preliminary findings of her research project at the British Mastitis Conference on 17 June 2026.