Harnessing data to support better breeding decisions has seen one Cumbria-based herd jump up the PLI ranking and improve overall herd performance. And there are more long-term benefits to genomic testing still to come.
TEXT EVA FEATHERSTON
A dedicated focus on herd genetics has positioned one Cumbria-based herd’s youngstock just shy of the top 1% in the UK for profitable lifetime index. The Bailey family decided to make genetic improvement a cornerstone of their dairy management strategy, and committed to using genomic testing to select high-performing cows and heifers, back in 2014. This forward-thinking approach has not only boosted their herd’s genetic potential, but is also resulting in better herd performance.
Producers John and Kate Bailey, and their son, fulltime vet Chris Bailey, run a 100-cow Holstein herd, plus 33 followers, at Moorhouse Hall Farm, near Wigton. The all-year-round calving herd averages 10,200 litres, at 4.17% butterfat and 3.36% protein, with a somatic cell count of 120,000 cells/ml. Cows are typically turned out to grass in April and are housed overnight from September, grazing during the day only throughout October.
Genomic route
The family decided to take the genomic route after listening to Nuffield scholar Neil Easter and learning how he bred a herd of Holsteins with youngstock performing in the top 1% for profitable lifetime index (PLI). Neil is a practising vet in North Yorkshire, but still provides consultancy on breeding and genetics for his brother’s dairy business, and has a considerable influence on the herd and dairy business.
The Baileys say PLI is an effective initial screening tool when making heifer breeding decisions. As an index specifically designed for use in the UK, it plays a key role in shaping the herd’s breeding strategy. There was no formal goal set by the family for the herd to rank in the top 1%, but achieving higher performance levels has been a natural progression during the past decade. The herd average for PLI at Moorhouse Hall Farm is 373, with first-lactation heifers achieving 497, and younger followers reaching a PLI of 583. One of the main advantages of genomic testing, according to John, is the increased reliability it offers compared to using traditional parent averages.
“We genomically test our heifers because, on average, you’ve got 35% reliability on most traits. In comparison, it’s possible to reach between 55% and 70% reliability using genomic data,” he explains. “The reliability is so much greater, and we always thought that genomic testing was the way to move both our and the national herd forward because it allows for accurate comparison.”
Using genomic data gives producers greater confidence and allows for more informed decision-making. John is able to breed from the top-performing heifers, using sexed dairy semen, and use beef semen for lowerranking animals. This ensures that only the best genetics are used to produce future generations of milkers.
Sire selection: the best genetics are used to produce replacement heifers
Real data
“Previously we had to find an excuse as to why a certain cow should or shouldn’t be bred to a dairy sire. But now, thanks to genomics, we have real data that gives us more confidence in identifying the bottom performers,” says John. By ‘weeding out’ the bottom 10% or 20% of the herd, he ensures a steady increase in the quality of milkers in the herd.
John and Chris select sires for use on their herd using AHDB’s Herd Genetic Report and bull search tools, picking the top performers in terms of milk yield and PLI, and indexes including HealthyCow and EnviroCow. They have recently changed milk contracts so are also adding butterfat and protein yield going forward.
John’s experience demonstrates the tangible benefits of genomic testing. He has seen a clear correlation between high-genomic-testing heifers and their lifetime milk production. “It’s not a perfect correlation, but there is a definite link,” he says. And his focus is on overall lifetime performance, rather than early-lactation yields, which reinforces the long-term value of genomics.
He stresses that longer lifespan is about more than just having older cows. “Genomic testing highlights cows that live longer without creating management issues. We’ve a lot of cows that are wearing so well that it would be difficult to guess their age. Looking at our genomic-test data, our older cows are ranking an average of 58 days above the national baseline. In comparison, followers are achieving 86 days above this baseline,” he says.
Focusing on traits such as lifespan, temperament and milking speed has further improved herd performance. This holistic approach to breeding has not only raised the herd’s PLI score but also visibly improved cow health and longevity. “Genomically-tested animals often outperform herds that do not test when it comes to key health and productivity traits,” says John. “The cow’s environment has a part to play, but I believe higher yields and better health and fertility are down to the genetic potential of our herd,” he adds.
Resilient milkers: John is keen to demonstrate that milk is a sustainable product
Genetic progress
Looking ahead, the Baileys recognise the huge opportunities that genomic testing, and genetic progress, have to offer, both in terms of the financial performance of their dairy herd and business, and the environment. Traits related to feed efficiency will play an important role in business sustainability, particularly as the dairy industry faces the challenge of achieving net-zero emissions.
Progress in this area is crucial for all dairy herds and the wider industry to demonstrate its commitment to environmental responsibilities, because these are values that are increasingly important to consumers. “It’s vital, from both an economic and environmental point of view, to show consumers that we’re doing something. We must stay ahead of the game and demonstrate that milk is a sustainable product,” says John.
“We’ve never aimed to climb the league table in terms of PLI,” says John. “But the herd has progressed from a top 20% position to now sitting just outside the top 1%. And this improvement is reflected in the performance of heifers as they join the milking herd.”
Genomic testing
Producers have been able to genotype heifer calves since 2012 and there’s a widening gap in genetic merit between herds that use genomic testing and those that use pedigree and performance data to select cows and heifers for breeding replacements.
AHDB data shows that herds that test between 75% and 100% of their heifers averaged a PLI of £430 for the 2023 calf crop, compared to just £237 for herds that test between zero and 25%. This £193 difference in PLI translates into a significant profit potential – around £19,300 for a typical 175-cow herd.
But analysis of actual margins from farm business accounts has revealed the advantage of a PLI difference of this magnitude to be more than £50,000. The uptake of genomic testing has surged during the past 12 years, with 100,000 dairy heifers now being tested annually, representing around 20% of all dairy replacements. This number is expected to grow by 15% in 2024, with adoption across Holstein, Friesian, Ayrshire, Jersey and Guernsey breeds.
Genomic testing can also correct parental-record mistakes and results in around 17% of heifers having their recorded sires updated, which directly influences breeding decisions. And producers who test also benefit from improved fertility. Non-testing herds average a fertility index of 3 points, while herds that genomic test females average 4.7. This helps to reduce calving intervals and non-return rates.
Find out more online at: ahdb.org.uk/knowledgelibrary/dairy-herd-genetic-reports.
AHDB herd genetic reports
Herd genetic reports (HGRs) are available to all UK producers who fully milk record. Producers can see the genetic potential of milking cows and youngstock, with information supplied on:
● PLI – a within-breed genetic index designed for allyear-round calving herds
● ACI and SCI – across-breed indexes designed for autumn- and spring-block calving herds
● Milk (kilogrammes)
● Fat and protein (kilogrammes and percentage)
● Inbreeding level
● Management traits – including SCC, mastitis, fertility, maintenance and lifespan indexes
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