John Edgar has spent his life breeding cows, but genetic testing is showing him there is more to his herd than meets the eye.

The farmer has discovered that some of his animals, which might previously have been overlooked when choosing which cows to breed from, have valuable traits that could help improve his herd.

He is among the farmers taking part in a £16.6m scheme to genetically test every cow in Northern Ireland, with the aim of breeding healthier, more productive animals while reducing emissions.

The Sustainable Ruminant Genetics (SRG) scheme analyses the genetic make-up of cattle to help farmers make better breeding decisions, with free testing available until the end of 2027.

Those behind the programme say it could improve animal welfare, reduce the need for antibiotics and help make food production more sustainable.

Edgar is in the thick of autumn calving on the farm near Trillick in County Tyrone that he runs with his father, Derek.

Until now, the decision about which cows to breed from in his 120-strong herd has been largely based on the milk they produce, including its butterfat content and volume.

Genetic testing gives him another layer of information, helping him identify characteristics that cannot necessarily be seen by looking at an animal or measuring its milk yield.

Samples are taken using a plastic ear tag, of which all calves in Northern Ireland receive at least two shortly after birth.

"Bulls have got full genotyping, genomics and data," he said.

"So really to have that information from the females or the cows on our farm is really, really important.

"It's something maybe that we should have been doing a long time ago."

The samples are then analysed to help farmers identify which animals are most likely to pass desirable characteristics on to their offspring.

For Edgar, that could mean making more informed breeding decisions and improving the performance of his herd over time.

And he has been surprised by what he has discovered.

"Quieter ones, or the ones that maybe just didn't stand out, actually had quite positive traits, and ones that maybe wouldn't have got bred from before are ones that we'll be looking for to breed from in the future.

"Hopefully we'll be able to make better decisions, breed better cows and get them on the ground quicker."

More than 6,000 farmers have already signed up to Sustainable Ruminant Genetics (SRG), part of the Department of Agriculture, Environment and Rural Affair's (Daera) Bovine Genetic Project (BGP).

It aims to breed cattle that are more efficient, whether by producing more and better-quality milk, reaching slaughter weight more quickly or having a lower environmental impact.

Victor Chestnutt, a dairy farmer from Bushmills in County Antrim, is heading the programme.

"Farmers are facing increasing pressures all sorts of ways and we have to deliver more environmental issues, and indeed more profitability for our farms.

"So this is a scheme to find out what the genetics are in every animal, so we can make better decisions when we are breeding."

He said food production needed to continue, but in a way that made better use of resources, getting "more from less".

Chestnutt also believes the scheme could boost Northern Ireland's standing on the worldwide agri-food stage.

"Northern Ireland is small enough to be able to do this for its whole herd and yet it's big enough for it to be meaningful," he said.

"So we could leapfrog the rest of the world and produce an index."

A similar scheme is also under way in the Republic of Ireland.

Genetic testing could also help farmers breed cattle that are less susceptible to certain diseases and health problems.

Noel Doyle, a vet from Irvinestown, County Fermanagh, said desirable traits included resistance to parasites, improved conformation to reduce lameness, and resistance to bovine tuberculosis (TB).

"The traits from a point of view of animal health would be to resistance against parasites, improved confirmation to reduce lameness, so legs and feet, and resistance to TB," he said.

"There's heritable traits for resistance to TB up to 11%, which would be useful in our fight against TB - at the minute we're struggling to get ahead.

"So if we can breed cattle which are going to be more resistant to TB, that'll be a step forward."

Healthier cattle could also mean fewer treatments are needed, potentially reducing antibiotic use on farms.

"If we've got healthier cattle as a result of this project, there could be less treatments required, and importantly, less antibiotics used on farm," Doyle said.

"If we can use less antibiotics on farm and more strategic use of antibiotics, it'll mean that those antibiotics are going to be useful on farm into the future.

"We want to avoid antibiotic resistance development, so the less antibiotics we can use on farm, the better."

Northern Ireland's agri-food sector is worth billions of pounds to the economy, and supporters of the scheme say its potential benefits extend beyond the farm gate.

Dale Farm is one of the largest dairy co-operatives on the island of Ireland.

Its chief executive Nick Whelan says improving the supply chain can help keep costs low for consumers and address other concerns they have.

"There's a growing awareness around climate change and all that brings.

"So from a consumer point of view, it's cost, it's sustainability, and I think animal welfare is also very high in consumers' minds.

"And being able to breed animals that are more resilient and more healthy in the supply chain is obviously a plus as well."

Back on the Edgar family farm, the third generation have already picked out their favourite calves and love spending time with the animals.

For their father, John, building the business and building better cows is all about building for their future.

"It's breeding healthy cows that last longer, that'll produce more and better quality milk for me.

"That's my breeding goals and using SRG and genotyping to do that is going to be a big step forward."