Milk production and herd health gains rise, finds NMR report

Dairy farmers are making significant gains in milk yield and fertility, while mastitis levels continue to fall, indicating higher production efficiency and a healthier national herd.

The latest National Milk Records (NMR) annual KPI report, drawn from a cross-section of 500 milk-recorded Holstein herds, shows lifetime milk yield a cow a day has risen nearly 25% over the past 15 years to 2025.

See also: How to help heifers join the milking herd and reduce stress

NMR director Ben Bartlett says this lifetime production increase is particularly impressive as it captures both output and efficiency across a cow’s life.

“Higher lifetime daily yield means more milk from fewer cows, lowering emissions per litre and improving the carbon footprint of the herd,” he says.

Milk yields

Milk yield averaged 13.1kg/day across Great Britain in 2025, up from 10.5kg/day in 2010, with the top 25% of herds achieving 15.4kg/day.

Over the same period, median annual yield a cow has increased from 7,665kg to 8,962kg. However, first-lactation yields have not kept pace with mature cow gains, and since 2020, median 305-day yields for first-lactation cows have dropped by 46kg.

Second-lactation yields have fallen by 10kg, while third and higher lactations have risen by 349kg and 449kg.

Ben attributes this to maturity and bodyweight. “The heifer will be perfectly healthy and able to conceive, but if not quite mature, then naturally her first lactation yield is not going to match those of the third and fourth lactation animals in the herd.”

However, he warns against focusing on a single KPI. Reducing age at first calving has been positive – the median now sits at 26.5 months – but if heifers calve too young and too light, early lactation yields can suffer.

“Ensure heifers reach around 85% of mature bodyweight before calving to avoid compromising early lactation yield,” he advises.

Health and fertility

Herd fertility has also improved. Since 2016, conception rates have risen from 34% to 40%, and calving interval shortened from 407 to 391 days.

Somatic cell counts (SCC) have also fallen as mastitis control improves. Median SCC dropped from 185,000 cells/ml in 2016 to 160,000 in 2025, and cows with no cell counts above 200,000 increased from 41% to 53%.

“That points to better mastitis control, stronger udder health and fewer hidden losses in the bulk tank,” says Ben.

Performance goals

Tightening up variation in performance not only improves the herd’s profitability but also the sustainability of a dairy farmer’s business.

Rather than chase maximum milk yield at any cost, Ben suggests farmers follow the “four Ps”. “You need to plan, persist, be patient and performance monitor.”

He advises using NMR’s report alongside farm-specific milk recording data to agree a bespoke plan, share it with vets, nutritionists, consultants and staff, and then track and adjust it over time.

Existing herd data can be used to drive improvement, particularly by identifying poorly performing cows and managing their exit, he adds.  

“It’s about the right milk, from the right cows, at the right time – all underpinned by accurate, timely data.”

The NMR has run its 500-herd KPI report annually since 2010, comparing the average, top 25% and bottom 25% of herds. Report for the year to August 2025, published by PAN Livestock Services and NMR.