By Farmer reporter

A Pembrokeshire dairy farm is screening the genomics of its heifer calves to select the best replacements for the milking herd.

Rearing replacements is one of the biggest costs on a dairy farm – rearing a calf from birth to calving is estimated to be around £1,800.

The Hannah family believes that testing their heifers for genomic traits is where big gains can be made in their spring calving herd.

They farm at Mountjoy, near Haverfordwest, where they milk a herd of 370 mainly New Zealand Friesian dairy cows and rear 200 replacement heifers.

As one of Farming Connect’s new demonstration sites, the farm has embarked on a project to improve the lifetime productivity of cows by selecting efficient genetics for the herd.

Working with Farming Connect, the business aims to rear only the most productive heifers, to prevent unnecessary costs.

The less productive animals can be sold, removing the unnecessary cost of rearing and, in turn, improving the genetics and performance of the dairy herd.

“Genomic testing could help us to select the best herd replacements to match the requirements of our system,’’ says William Hannah, who farms with his wife, Heather, and his parents, Tom and Mary.

“We feel there are real gains to be made from this, by eliminating poor genetics so that only the very best animals are retained within the herd.’’

Industry figures show that 14.5 per cent of female youngstock fail to reach their first calving, whilst 33 per cent don’t make it to their second lactation. Dairy cows don’t start paying back through milk sales until after the second lactation, by which time a vast amount of money and effort have been invested.

Simon Pitt, dairy technical officer with Farming Connect, who is overseeing the project at Mountjoy, says genomic estimated breeding values can be calculated at birth and, as it has a high accuracy, a strategy that utilises these advantages can be used to determine which female calves will be the most cost effective and the most productive.

Compared to traditional herd genetics, which is 18-25 per cent accurate, genomic testing is 50-60 per cent accurate (SCI-Spring Calving Index), he points out.

“Genomic selection offers many advantages with regards to improving the rate of genetic gain in dairy cattle breeding programs, one benefit of interest to this project is that genetic testing can predict a greater accuracy of predicted genetic merit for young animals,’’ says Mr Pitt.

Health benefits are also flagged up through testing; as Mountjoy sits in a high-risk TB area, among the traits of interest are TB advantage and calf survival index.

Progress on the Farming Connect project will be share with farmers on the Farming Connect website and social media channels whilst the Covid-19 lockdown restrictions are in place.