The milk from Irish grass-fed dairy cows is more nutritious than that from cows in conventional indoor feeding systems, according to a Teagasc study.

Researchers from Teagasc and Food for Health Ireland (FHI) have discovered that dairy cows that operate on an Irish grass-fed system produced milk with higher percentages of omega-3 and conjugated linoleic (CLA) fatty acids compared with cows fed medium and low proportions of grass.

The peer-reviewed study has been published in the Journal of Dairy Science and is available here.


According to the research, Irish grass-fed milk has an 83% increase in omega-3 fatty acids, 141% increase in CLA, the highest levels of unsaturated fatty acids and the lowest levels of saturated fatty acids.

There were three dairy farm systems compared during the research, including one where cows had a high grass allowance diet, typical of that operated by Irish farmers, a medium grass allowance diet and a low grass allowance diet, most commonly operated around the world.

Grass-fed milk has higher percentages of omega-3 and conjugated linoleic (CLA) fatty acids, according to Teagasc. \ Philip Doyle

“While grass-based feeding systems are the most common source of dairy produce here in Ireland, the levels of fresh grass fed to dairy cows in countries such as the United States, Germany, Austria and Denmark is significantly less than in Ireland,” said Teagasc Moorepark PhD researcher Mark Timlin.

Teagasc highlighted that while previous research has shown that pasture-based, grass-fed feeding systems are more natural and better for the environment, allowing cows to express their natural behaviours by grazing, the latest study is the first to highlight the nutritional benefits.


FHI centre director Dr Nessa Noronha said the nutritional findings are part of a “wider piece of research, which investigate the composition, functionality and sensory characteristics of Irish grass-fed dairy and the impact of the cow’s diet on human health”.

The Irish outdoor grass-fed dairy system is different from that in most other countries, said Teagasc. \ Roan Murray

“Irish grass-fed is a claim that is gaining more resonance with consumers as it is perceived as more natural and sustainable.

"The Food for Health Ireland team is committed to advancing the scientific credentials of Irish-grass fed dairy to help maintain and support Ireland as leaders in the production of sustainable, nutritious and tasty food – all of which are demanded by consumers,” she said.

According to Teagasc, the study gives consumers in Ireland and abroad a reason to buy a premium Irish product – grass-fed milk.