Using genomics to future proof your herd

Genomic testing and an effective, tailored approach to breeding, has lifted Hillhead of Covington's herd’s genetic merit into the top 15% across the UK.

Making the right breeding decisions can make a huge difference to farm profitability so understanding the genetic make-up of your herd and the available options to inform your decisions is a great place to start.

Based in Lanarkshire in Scotland, William Baillie runs a high yielding, all year round calving herd at Hillhead of Covington where he started with 50 cows 25 years ago and has grown the herd to 400 pedigree Holsteins.

Since 2019, genomic testing has played a part the herd’s development. Coupled with an effective, tailored approach to breeding, the team have lifted the herd’s genetic merit into the top 15% across the UK.

Dairy sire selection at Hillhead is strongly focussed on £PLI and management traits. “Fertility, lifespan and cell count all have a big impact,” says William. “We were also on a liquid milk contract there was little incentive to produce milk solids, but I felt that the industry was changing, and that we really should try and breed for higher milk solids. We have now moved to a milk solids contract.

“At Hillhead, we have been crossing a few cows with poorer milk solids to a Jersey. We have been trialling a group of Jersey cross Holstein heifers for the past year and I have been really impressed with the milk yield and quality. I’m hoping the ones we breed from higher £PLI cows and proven Jersey bulls will be even better.”

For William, the decision to explore genomics came from a wish to accelerate the genetic development of the herd. He now successfully uses genomic testing to inform and tailor his breeding programmes.

“We did some genomic tests three years ago and I was unsure of the benefits, but when you see the results, they are accurate, and they have done what they said – so I’ve got the confidence to carry on and do more of them,” says William.

“For the past four years we have used nothing but genomically tested young bulls, I’ve been really impressed with how they’ve turned out and the increase in genetic merit; they’re so far ahead of the proven sires.

“Cows are now more even, well balanced, with less extremes as a herd.  Dairy semen is all sexed with the top third of the cows, and all maiden heifers bred to dairy and the remaining cows, alongside any cows +125 days in milk, bred to beef semen.”

The top heifers are selected based on £PLI. While conception rates are 5% lower with sexed semen, William is still able to ensure enough heifer calves to increase the herd.

In 2018, Zoetis fully funded genomic testing for 80 of Hillhead’s heifers. These genomic tests were assessed by AHDB’s genomic evaluation service and, based on these results, 79 were mated using Genus’s GMS programme. Initial mating selections based on parent average £PLI were compared to those based on the Genomic £PLI and showed 48 heifers had different first choice sires.

The shift in first choice sires can be due to parentage correction or the difference between siblings, where offspring take on different parent genes.

The results from the programme at Hillhead are impressive. The milking herd’s average PLI is £165, which rise for £369 for the youngstock. PTA for fat shows a corresponding increase from 7.6kg to 18.5kg, and protein from 6.9kg to 13.4kg.

“The milking herd at Hillhead is very good on £PLI, production, lifespan and SCC ranking is in the top 25^th percentile when benchmarked alongside other herd genetic results,” says Marco Winters, AHDB’s Head of Animal Genetics.

“As William highlighted in his breeding policy, constituents need focus and this shift in breeding can be seen in the genetics of Hillhead youngstock, making good progress with milk and constituents in the top 15^th percentile.”

While the cost of genomics testing can be a barrier for some, William looks at it as a long-term return on investment. Testing has helped to confirm bloodlines and inform the breeding decisions within the herd. For William and the team at Hillhead, the use of genomic testing is accelerating improvements and ensuring high quality, profitable cows.

Genomic evaluations

Genomic testing produces an estimate of an animal’s genetic potential and gives dairy farmers additional information to help make informed breeding decisions. Available through AHDB for Holsteins since 2012, testing has been extended to Friesians, Ayrshires, Jerseys and Guernseys.

Testing provides young animals with more reliable proofs, with accuracy rates of around 70% for black and white breeds. This helps to ensure that superior genetics are coming through in the herd.

Female lines can be assessed and for those running a flying herd, it can give greater control over which genetics are being brought into the herd.

Genomics testing is a useful screening tool for youngstock, helping to validate or identify parentage and finding known genetic recessives. In some cases, it can be used as a preselection for rearing.

Heifers with the poorest genomic results can be removed from the herd to save on rearing costs.  Results can inform breeding decisions such as selecting which heifers to put to dairy semen and, as seen at Hillhead of Covington, in choosing the dairy sire selected for individual heifers.

Genomic evaluations are set-up by AHDB Dairy funded through the levy and provides the backbone of the genomic services offered in the UK.

Several companies provide genomic testing with evaluations calculated by AHDB as part of the service for free for females. However, bulls incur a small charge to make their genomic proofs official.