Tactical Grazing – Making Smarter Turnout Decisions
Following on from our recent blog on pasture management for the good doer, we’ve looked at how to restrict intake. This time, we’re focusing on something often overlooked- when and where your horse grazes, and how small changes in turnout decisions can influence sugar intake from grass.
Grass is the biggest and most variable source of sugar in the equine diet, particularly for those prone to weight gain or laminitis. While we often focus on restricting access, being more tactical with turnout can help make grazing a more sustainable part of the ration.
Why Timing Matters
Grass doesn’t contain a fixed level of sugar, it changes throughout the day in response to light and temperature.
Sugars are produced through photosynthesis and tend to accumulate during daylight hours, meaning levels are often higher later in the day and lower after periods of darkness.
As a result, where appropriate:
● Early morning turnout can be a useful strategy
● While late evening or overnight grazing may be beneficial in some situations this should always be considered alongside the day’s weather conditions.
However, this isn’t a one-size-fits-all rule. Environmental conditions can override these patterns, which is why a flexible approach is key.
Watch the Weather
Weather plays a significant role in how much sugar accumulates in grass, often more so than the time of day alone.
Conditions that may reduce sugar accumulation include:-
- overcast days
- shaded paddocks (e.g hedge-lined or tree-lined fields)
- Periods of active growth where conditions support both photosynthesis and growth
In contrast, more caution is needed when:
- Cold nights (below 5°C) are followed by bright sunny days
- Frosty mornings with clear skies
- Periods where growth is limited but sunlight is high
Under these conditions, grass continues to produce sugars but cannot use them effectively for growth, leading to accumulation. This is often referred to as plant “stress” where growth is limited more than photosynthesis. Under these conditions, sugar accumulation can occur even when grass does not appear lush or rapidly growing.
Location Matters Too
Not all areas of a field are equal. Small changes in where horses graze can influence sugar intake:
- Shaded areas tend to accumulate less sugar due to reduced light exposure
- Woodland or hedgerow turnout (where safe) can offer lower sugar grazing options
- Exposed, sunny paddocks are more likely to have higher sugar accumulation
This doesn’t mean avoiding grass altogether, but it does highlight the value of thinking about where grazing is taking place.
Tactical Doesn’t Mean Unlimited
While timing and location can help reduce sugar intake, it’s important to remember that grass intake is still difficult to control.
Even under “lower sugar” conditions, intake can still be significant, particularly in good doers. Importantly, “lower sugar” does not mean “low risk” total intake and individual sensitivity still play a significant role. Equally, reducing turnout time alone can sometimes backfire, with horses compensating by eating more quickly .
For this reason, tactical grazing works best when combined with:
- Ongoing monitoring of weight and condition
- A balanced forage-based ration
- Awareness of individual risk (e.g EMS, laminitis history)
Bringing It All Together
Tactical grazing isn’t about finding a perfect window where grass is “safe” — it’s about making informed, day-to-day decisions that help reduce risk.
By considering:
- Time of day
- Weather conditions
- Field layout and shade
…you can take a more proactive approach to managing sugar intake, without necessarily removing grazing altogether.
Take-Home Points
● Grass sugar levels vary throughout the day and with environmental conditions.
● Early morning or late evening turnout may help reduce sugar intake but always consider the wider conditions.
● Environmental stress (e.g cold nights, drought, poor growth) can increase sugar accumulation in grass.
● Overcast days and shaded paddocks can offer lower sugar grazing opportunities.
● Frosty, bright conditions and cold nights followed by sunny days increase risk.
● Tactical grazing supports but does not replace overall ration and weight management.
Tactical Grazing – Traffic Light Turnout Guide
GREEN – Lower Risk Conditions
More suitable for turnout (with appropriate monitoring)
- Overcast or cloudy days
- Grazing in shaded paddocks (hedges, trees, woodland edges)
- Early morning turnout (after mild nights)
- Late evening / overnight turnout (context dependent – consider daytime conditions)
- Periods of active grass growth (mild temperatures, adequate moisture)
Why? Lower light levels reduce photosynthesis, meaning less sugar accumulation in the grass
AMBER – Use Caution
Turnout may be appropriate, but monitor closely
- Warm, sunny days with consistent overnight temperatures
- Mixed weather (sun and cloud)
- Moderate grass growth periods
- Days following bright sunshine where sugars may remain elevated into the evening
- Horses with some metabolic risk but currently well managed
Why? Sugar levels may be moderate — not extreme, but still significant depending on conditions and intake
RED – Higher Risk Conditions
Best to restrict or avoid turnout where possible
- Frosty, bright mornings
- Cold nights (<5°C) followed by sunny days
- Bright, sunny spring and autumn days
- Periods of plant stress (e.g drought, poor growth, nutrient deficiency)
Why? Grass continues to produce sugars but cannot use them effectively for growth, leading to accumulation
Important Reminders
- Grass sugar levels are influenced by multiple interacting factors — time of day, light, temperature, and plant stress so no single rule applies every day
- Tactical grazing helps manage sugar intake but does not control quantity eaten
- Horses may compensate by eating faster if turnout is restricted
- Always pair turnout decisions with:
○ Regular weight and condition monitoring
○ A suitable forage-based ration
○ Awareness of individual risk (EMS, PPID, laminitis history)