Study shows breeding can help cut dairy farm emissions

A new study suggests that breeding could play a bigger part in reducing greenhouse gas (GHG) emissions from dairy farming.

The research, commissioned by AHDB and undertaken by Promar International, looked at how genetics can help lower a farm’s carbon footprint.

It found that herds using targeted breeding could reduce emissions by up to 16% over five years.

The study focused on the EnviroCow index, which ranks animals based on traits linked to environmental impact.

Herds that selected bulls with higher EnviroCow scores saw steady improvements over time. On average, this led to carbon footprint reductions of 8.5% to 16% over five years.

This progress assumed an average emissions intensity of ~1.01kg CO₂e per kg of fat and protein-corrected milk (FPCM).

Dr Jordana Rivero, principal sustainability consultant at Promar International, said the results were ‘really promising’.

She explained that genetics account for more than one third of the variation in emissions between dairy farms. She said that EnviroCow showed the strongest link to lower emissions compared with other genetic measures.

AHDB developed EnviroCow around five years ago to help farmers breed more environmentally efficient cows.

Marco Winters, Head of Animal Genetics at AHDB, said the study provides useful independent evidence that the index is working in practice.

He said:

“The link between the index and carbon footprint isn’t perfect, but, like all genetic improvement, the benefits come at little additional cost to the farm, are permanent and accumulate over time.”

The study also found strong links between lower emissions and other breeding indexes, especially the Profitable Lifetime Index (£PLI).

Dr Rivero said:

“£PLI and EnviroCow are highly correlated, so the national herd has been moving in the right direction.”

Mr Winters confirmed that farmers had substantially improved £PLI over the past 20 years.

He said that, as an economic index, it was known to improve efficiency, but would also have a beneficial impact on emissions.

Our advice remains that farmers should continue to focus on breeding-for-profit indexes like £PLI, while also looking to improve EnviroCow where possible.

Don’t focus solely on emissions as a trait. A breeding policy should be well-rounded and other important traits must be considered.