Measuring grass: Drive performance with data-driven decisions

Grass is one of the most valuable yet under-measured crops. If well-managed, it’s cost-effective, nutritious, and can significantly boost your farm’s bottom line.

But some still rely on instinct rather than data when making grazing decisions, not maximising the full potential of their pasture. By measuring grass regularly, you can improve feed efficiency, animal performance and pasture longevity.  

Why measuring grass matters

Maximise your natural asset: grassland

Well-managed grass means less reliance on expensive bought-in feed. Every extra day your livestock graze high-quality pasture is money saved, and performance gained.  

Make better decisions with data  

Measuring grass gives you real-time data to support key management decisions:  

• How much feed is available?  

• How fast is the grass growing?  

• Is the overall cover increasing or decreasing?  

With accurate data, you can avoid overgrazing, balance grazing with plant growth and ensure your livestock have enough feed throughout the season, without compromising pasture health.  

William Fleming from Germinal says:  
“Without measuring grass you can’t manage it accurately, and given the challenging season, good data helps drive business decisions.” 

Improve grazing efficiency

By knowing exactly what’s in front of your livestock, you can:  

• Match demand with supply.  

• Maintain optimal residuals after grazing, which helps the pasture recover faster. 

• Extend the grazing season, which reduces reliance on stored feeds. 

• Drive milk production of daily liveweight gain, depending on your system. 

A more efficient grazing system leads to better animal performance and a more resilient business.  

Real success: Farmers benefiting from measuring grass

Stuart Evans – Carmarthenshire  

Stuart runs an organic dairy farm where every resource counts. Unable to use chemical fertilisers or pesticides, he relies on undersowing grass and clover with arable crops to keep his soil healthy and productive.   

Measuring grass and keeping detailed records helps him plan for grazing and reseeding. As a result, Stuart has increased herd size, maintained high milk yields and kept his system profitable and sustainable.  

James Tweedie – Cumbria  

James manages a 400-cow dairy farm where grass measuring is routine. By tracking grass growth and using the data to guide decisions, James can produce more grass, reduce the need for brought-in feed and keep his business efficient and resilient.  

Whether using a plate meter or walking your fields, the key is consistency. The more you measure, the more confident and informed your grazing decisions become.  

How to measure grass?

Grass is measured in kilograms of dry matter per hectare (kg DM/ha). This figure accounts for the water content in fresh grass, giving you a picture of the feed available. 

For the most accurate results, assess pastures every 7-10 days. Regular measurements help you stay on top of grass growth, adjust grazing plans and make informed decisions about supplementary feeding.  

Here are some common grass measurement methods:  

Tip: For mechanical plate meters, you can estimate dry matter by multiplying compressed height by 250kg DM/cm. For example, 10cm x 250 = 2,500kg DM/ha. After grazing, aim to leave around 1,500kg DM/ha, giving you 1,000kg DM/ha of available feed. 

Need advice on forage planning 

Measuring grass is simple, but choosing the best approach for your grazing system takes careful consideration. Our regional experts are here to guide you.