Extending Grazing Season
Housing cattle too early raises costs and emissions.
Extending the grazing season boosts grass use and cuts emissions without hurting yields.
The Climate Issue
Grazing is one of the most efficient ways to feed dairy cows. Fresh grass is high in energy, supports strong milk yields, and grows back quickly when well managed. It’s also lower in emissions than any other feed.
But in many systems, cows are housed for long periods, sometimes up to five months a year. During housing, more meal is fed, slurry builds up, and emissions rise from storage and feed imports. Each extra day indoors costs more and pollutes more.
The Solution: Extending Grazing Season
Extending the grazing season means turning cows out earlier in spring and keeping them at grass later into autumn. It builds on what nature already gives us: solar energy, homegrown feed, and strong root systems.
By grazing even 10 more days each year, farms can reduce greenhouse gases and feed bills. Grass replaces imported meal. Cows walk and spread manure naturally. Slurry is avoided. Trials show each extra 10 grazing days cuts GHG by up to 1.7 %.
Key Benefits when Extending Grazing Season
Cut Emissions
Grazing longer reduces emissions from housing, feeding, and storage. It avoids methane from stored slurry and shrinks the carbon footprint of imported feeds.
Save Costs
Fresh grass is the cheapest feed. Grazing 10 extra days saves about €1.80 per cow – or €180 on a 100-cow farm. Those savings stack up across the season.
Yields from Grass
Longer grazing means more energy from grass and less from meal. Milk yields stay strong, while grassland management improves year-on-year.
Impact of Extending Grazing Season
Switching to a longer grazing season isn’t just a calendar tweak. It’s a proven way to improve animal performance, cut emissions, and lower daily costs.
Teagasc trials show that grazing an extra 30–60 days per year can:
- Cut GHG emissions by 5–10 %
- Save €540–€1 080 in feed costs for a 100-cow herd
- Improve pasture utilisation and regrowth
- Lower indoor slurry production by 15–25 %
See the table below for the impact of different grazing-extension scenarios.
|
Scenario
|
Days at Grass
|
Extra Milk Revenue
|
GHG Emissions
|
% GHG Reduction
|
|---|---|---|---|---|
|
Baseline |
241 |
- |
0.960 kg CO₂-eq/kg milk |
0% kg CO₂-eq/kg milk |
|
Add 7 Days |
248 |
€1,465 |
0.936 kg CO₂-eq/kg milk |
1.04% kg CO₂-eq/kg milk |
|
Add 21 Days |
262 |
€2,930 |
0.936 kg CO₂-eq/kg milk |
1.04% kg CO₂-eq/kg milk |
Considerations
Weather & Soil
Grazing longer depends on mild weather and well-drained soils. Heavy rain or poor pasture can damage swards. It’s essential to avoid poaching and protect paddocks during shoulder seasons.
Infrastructure & Planning
Good access lanes, shelter, and paddock rotation help support spring turnout and autumn grazing. Reseeding, liming, and fertiliser timing can also improve resilience.
Grazing Management
Mob grazing and block rotation work best. Planning ahead – including closing paddocks early – ensures enough grass is available when cows go out.
Implementation
Extending grazing takes planning, but the gains are significant. With good soil, rotation, and infrastructure, many farms can hit +30 or even +60 days per year. Here’s how to get started.
- Target early turnout. Close paddocks early in autumn so you have grass cover ready for spring. Aim for 30–40 % of grazing days by early March.
- Improve access. Repair laneways, add back-fences, and plan entry points to avoid poaching in soft conditions.
- Use rotation planner. Match grass supply to demand. Rotate regularly and avoid overgrazing. Feed budgets and paddock walks support long-term success.
Behind the Research
ODOS Tech was founded by Cian White and Alejandro Vergara, two sustainability specialists with deep expertise in agricultural climate action.
Cian, a researcher at Trinity College Dublin with a background in environmental science, works on restoring nature to increase biodiversity on farms by using satellite images to track trees, hedgerows, and other habitats. Alejandro, a PhD researcher at University College Dublin, helps farmers measure their carbon emissions footprint and implement mitigation strategies to reduce their impact.
Together, they helped lead the carbon and nature-based work for the Farm Zero C project at Shinagh Farm, one of Europe’s first net-zero dairy pilots. At ODOS, they build smart, science-based tools to help agri-food businesses protect the environment and restore nature.
Research
Teagasc Pasture Trials
Teagasc has trialled extended grazing across dairy systems and found each 10-day gain cuts emissions by ~1.7 % and improves grass utilisation, milk solids, and fertiliser efficiency across the board.
Tirlán Grazing Reports
Industry data shows that farms reaching 270+ grazing days per year report better margins, lower feed bills, and more consistent pasture growth over time.
IPCC and EU Policy
Longer grazing aligns with climate-smart practices recommended by the IPCC and EU. It supports biodiversity, improves nutrient cycling, and reduces emissions without sacrificing productivity.
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