For years, crossbred dairy farmers – and particularly those managing grazing herds – have watched from the sidelines as the purebred world reaped the rewards of genomic testing. The wait is now over with the launch of a new crossbred genomic evaluation from AHDB.

Genomic testing has quietly transformed the purebred dairy sector since it became widely available in the UK around 2013 and 2014. The ability to analyse thousands of DNA markers in a young animal and predict her future genetic contribution – long before she has ever milked – has accelerated genetic progress at a rate that simply wasn’t possible when breeders were relying on performance data alone. 

AHDB has spent the best part of four years developing the evaluation framework that underpins this new crossbred evaluation, and the conversations driving it go back even further. The result is an extension of the existing genomic offering – one that already covers Holstein, British Friesian, Ayrshire, Jersey, Guernsey and Scandinavian Red animals – to now include any crossbred animal that contains at least 51% genetic material from those breeds. 

Filling a Significant Gap

Until now, crossbred farmers have had to rely on phenotypic data alone – what an animal looks like and how she performs – to make breeding decisions. Useful as that is, it has real limitations. It tells you how an animal has performed, but not what she is likely to pass on to her progeny. And for the grazing farmer who manages seasonal systems with tight breeding windows and long generation intervals, that lack of genetic clarity carries a real cost. 

“Their way of ranking at the moment is limited,” explains Will Astley, Cogent’s Grazing Product Lead. “We’ve been working off phenotypic data alone. And we know that, although it's useful, it has its inaccuracies. It isn’t telling us genetically what the animal is going to pass on to her progeny.”

The practical consequence of this gap has been that many grazing farmers have felt compelled to wait until heifers reach their first lactation before committing to dairy matings – simply because they didn’t have the genetic information needed to make earlier decisions with confidence. That delays genetic progress and extends the generation interval, slowing the rate at which herds can improve. 

What AHDB Has Built

The new evaluation is an extension of AHDB’s existing genomic framework, now expanded to include crossbred animals containing at least 51% from the purebred breeds originally offered for genomic testing. That covers the vast majority of crossbred dairy cattle in the UK.

Underpinning it is a single-step, across-breed analysis – widely regarded as the gold standard methodology in genomic evaluation. Rather than treating each breed in isolation, this approach combines DNA data, real-world performance records and pedigree information in a single model, allowing animals from different breed backgrounds to be assessed fairly and accurately within the same system. 

Crucially, AHDB has built a reference population that includes not just purebred animals but crossbred animals too, making the predictions genuinely relevant to mixed-breed herds rather than simply adapted from purebred context. That distinction matters: a crossbred animal evaluated against a crossbred reference population will yield far more reliable predictions than one assessed against a purebred benchmark. 

AHDB recently passed the one million genotype mark across its genomic database – a milestone that reflects the depth of data now underpinning these evaluations and strengthens the reliability of the predictions they produce. 

More Than Double the Accuracy

The accuracy improvement genomics delivers over traditional parent averages is substantial. Parent average matings in crossbred herds currently run at around 20% accuracy – meaning two in ten breeding decisions are as well-informed as they could be. Genomic evaluation increases that accuracy to approximately 50% for crossbred animals in the current evaluation, with the expectation that this will improve further as the reference population grows. 

Will Barber, Dairy and Genomics Manager at Cogent, explains the significance of that shift in practical terms.

“We’re making genetic gain on all those animals with parent averages, but it’s only two in every ten that we’re getting right every time. Genomics lifts that to around five in ten for a crossbred animal. All of a sudden, we’re really accelerating that progress – we’re going to be able to get more matings correct, which means quicker progress, which ultimately means better returns for the farmer.”

Genomic testing also verifies parentage – confirming that animals are correctly linked to their recorded sire and dam. In crossbred herds, where record-keeping can be complex, that verification strengthens confidence in every genetic prediction and every breeding decision that follows it. 

The Traits That Matter to Grazing Farmers

The traits covered by the new crossbred evaluation have been chosen with practical relevance in mind. Alongside production measures -milk kilograms, fat and protein kilograms, and fat and protein percentages – the evaluation includes lifespan, somatic cell count, fertility index and mastitis resistance. 

For a grazing farmer, that breadth is significant. Grass-based systems place particular demands on an animal: she needs to be able to walk, cycle back into calf efficiently within a tight seasonal window, to stay healthy without high intervention costs, and to convert grazed grass into milk solids effectively. Knowing the genetic potential of each heifer across all of those dimensions – before she has ever been served – opens up a fundamentally different approach to herd management. 

Every season spent wating, is a season in which genetic progress is deferred. Genomic evaluation allows earlier, more confident decisions, meaning the best genetics can be identified and acted up sooner – and the gains that follow begin compounding that much earlier.

With AHDB’s new crossbred genomic evaluation, the wait‑and‑see era is over. Crossbred herds can now make clearer, earlier and more confident breeding decisions than ever before - unlocking faster genetic gain, stronger herd performance and greater long‑term resilience. For farmers who want to stay ahead of the curve, the next step is simple: start genomically testing your heifers through your semen supplier. Now is the time to put the power of genomics to work in your herd.