How it works
How Grazey works
Grazey consists of two modules that work together: the NSC monitor estimates the grass-sugar risk of your pasture, and Measurements records the real condition of your horse. The first gives you a forecast, the second gives you reality — and you bring the two together.
Module 1
The NSC monitor
The NSC monitor calculates a daily score for the amount of sugar in your grass: the non-structural carbohydrates (NSC) — the sum of simple sugars, fructan and starch. These are the carbohydrates that drive the risk of being overweight, insulin problems and laminitis. The score looks five days ahead, so you can see not just how things stand today but plan the coming week too.
Sugar, fructan and starch: what's the difference?
Among horse owners, "fructan" is often used as a catch-all term for everything that can go wrong with grass sugar — but it's actually just one of three carbohydrates that count. Simple sugars and starch are absorbed directly in the small intestine and are the biggest direct trigger for a high blood sugar and insulin spike. Fructan is a storage sugar the grass produces as a reserve, especially under cold stress; it isn't broken down in the small intestine but fermented in the hindgut, and in large amounts can disrupt the gut flora. Precisely because fructan is the storage sugar, its concentration in grass can climb much higher than that of simple sugars — an important reason for its poor reputation.
The daily cycle: photosynthesis and use
Grass is essentially a small sugar factory. During the day it converts sunlight into sugars through photosynthesis — the more light, the more it produces. At night the grass uses those sugars to grow and recover, so the level normally drops again. That's why sugar content is usually lowest just before sunrise: the plant has been using it up all night.
Cold weather changes this pattern. Below around 5 °C, grass barely grows, so night-time use nearly stops while daytime production carries on as usual. The grass stores the surplus sugar as fructan — a kind of emergency reserve for when growth picks up again. That's why a sunny day followed by a cold night is such a well-known risk moment: lots of production, little use.
How it determines the score
The score comes from two types of information:
The weather for your location
As described above, the NSC level closely tracks light and temperature. Grazey therefore fetches the weather forecast for your pasture's location and translates it into the expected sugar, fructan and starch progression.
Your pasture's characteristics
Not every pasture reacts the same way to the same weather. That's why you provide a few characteristics: grass type, sward length and whether the pasture is fertilised. These help determine how strongly the sugar levels rise.
Why it's an estimate
Important: the NSC score is an approximation, not a measurement. Grazey doesn't measure the sugar in your actual grass — that would require a lab test every day.
Instead, it calculates the score from the factors we know drive sugar content: weather, season, grass type, management. What the model doesn't know is your specific situation down to the last detail: the soil, the exact grass mix, your pasture's microclimate, its grazing history.
That's why the score is a good starting point, not a final verdict. That's exactly where you come in.
Your horse, your thresholds
The score itself is neutral. What gives it meaning is how sensitive your horse is. A warmblood simply doesn't have the same sensitivity as a hardy breed. That's why you choose a sensitivity level when setting up. That level determines at which score the colours on your dashboard switch from calm to warning. For a sensitive horse, the warning colours kick in sooner.
And you're not locked into that setting. You can shift the thresholds for each warning colour yourself. Do you see your horse already reacting while the score is still green? Move the threshold down. Do you see its weight and Body Condition Score improving? Then you might consider moving it up. The longer you use Grazey, the better the colours will fit this particular horse — and that's what the second module is for.
Module 2
Measurements
Where the NSC monitor looks ahead, Measurements records what you actually observe. You track your horse's condition yourself, and see its progression over time in charts.
What you record
You can track five things:
BCS — Body Condition Score
An estimate of your horse's fat coverage, from too thin to too heavy.
CNS — neck score
The condition of the neck crest, an early indicator for metabolic problems.
Weight
Measured, for example, with a weight tape.
Weekly exercise
The number of kilometres your horse covers.
Turnout
How much time your horse spends outside in the pasture per part of the day — night, morning, afternoon, evening.
For each of these you see the trend: not a single isolated measurement, but the direction it's heading. For each metric you decide yourself whether to track it and how often you want a reminder.
The digital pulse check
A recurring reminder
The digital pulse check is included separately. This isn't a graph, but a recurring reminder to feel the arteries near the hoof — a quick, manual check that's easy to forget, but which gives a strong indication of problems in your horse. Grazey keeps it on your radar.
Where the two modules come together
The NSC monitor gives you a forecast; Measurements gives you the outcome. By placing the two side by side, you can base your thresholds on your own observations instead of on a gut feeling.
Do you see in your BCS chart that your horse is gaining weight during a period the monitor mostly rated green? Then you know your situation could use finer tuning — and you shift your thresholds based on evidence you've gathered yourself.
That's how Grazey turns from a general calculation into your own, calibrated instrument.
Ready to get started?
Create an account, add your pasture and see today how the sugar risk unfolds.
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