Managing Grass Intake in Spring for the Good Doer or Metabolic Horse

• Daily Forage Requirements
• Estimating Forage Intake
• Why Grass Intake Needs Managing
• Strategies to Control Grass Intake and Encourage Movement
• Additional Considerations - Vitamin E

Managing Grass Intake in Spring for the Good Doer or Metabolic Horse

In the UK, grass, hay, or haylage commonly make up the majority of a horse’s forage intake. The minimum daily forage requirement for any horse is 1.5% bodyweight on a dry matter basis. For most horses, we recommend providing constant access to forage to support digestive health and promote natural grazing behaviours. However, for overweight horses or particularly good doers, this is not always possible due to the risk of excess weight gain and obesity. So, for these horses, we aim to feed at or slightly above 1.5% body weight in forage per day to support weight management.

Good doer: we refer to a horse being a good doer when they maintain their body fat well on a small quantity of feed, or a forage only diet

Estimating Forage Intake

It is difficult to accurately gauge your horse’s daily forage intake, particularly if they have access to grass pasture or are housed in groups. However, it is recommended to weigh your horses hay intake over a 24-hour period, to better understand forage consumption. Grass intake is highly variable between horses, however research has provided the following intakes for the average horse as a guide:

• 112.5g per hour on poor grazing
• 225g per hour on average grazing
• 337.5g per hour on good grazing
• 450g per hour on excellent grazing

By understanding your pasture quality, and estimating daily forage intake, this gives an indication of whether reducing forage intake for your overweight horse is an appropriate option as part of their weight management plan.

Why Grass Intake Needs Managing

The pastures used for grazing horses in domestic management settings often contain improved grass species, which increases in nutritional value as we enter spring. Fresh green pastures can contain high levels of non-structural carbohydrates (NSCs), consisting of simple sugars, and fructans. When consumed in large volumes, this can increase fructan fermentation in the hindgut, increasing the risk of pasture-associated laminitis. What seems like the obvious solution is reducing turnout time. However, some horses will learn that they only get limited time at pasture and gorge on grass for the period that they are out. In fact, some ponies have been shown to eat 1% of their body weight in grass in just 3 hours. Therefore, the following grazing management methods can be considered as alternative ways to manage grass intake.

Strategies to Control Grass Intake and Encourage Movement

Muzzling

Using a grazing muzzle for horses is an effective way to reduce grass intake and manage weight, as muzzles can decrease pasture intake by up to 80% while still allowing the horse to trickle feed. However, grazing muzzles should not be used 24/7, as this may restrict forage intake too much and negatively impact digestive health. For horses living out at pasture full-time, we suggest using the muzzle during daylight hours when grass sugar levels (NSCs) are higher and removing it overnight.

Strip Grazing

Strip grazing horses is widely used to manage grass intake, particularly when introducing horses to rested paddocks. By sectioning off a strip or corner of the field and gradually increasing grazing access every few days, you can effectively limit grass intake and control calorie consumption.

Track System

Using track systems for horses is another increasingly popular grazing and weight management method. A recent study comparing overweight ponies on track systems versus strip grazing found that ponies travelled significantly greater distances on a track system (Kirton et al., 2024), encouraging increased movement and calorie expenditure. While no immediate differences in body fat measures were observed over 4 weeks, longer-term use may support weight loss. Another study reported that horses on track systems lost an average of 3.4% of their body weight, compared to those on traditional paddock grazing who gained on average1.5% (Cameron et al., 2025). Tracks with hills or varied terrain may further enhance weight loss and fitness.

Graze with Other Horses or Sheep Accordingly

Turning out with other horses or sheep can help keep pasture under control and encourage natural movement as horses interact and display social behaviours.

Turn out in Dry Lot with Hay

When pasture quality is high or for horses at greater risk of metabolic conditions, turning out in a dry lot or arena and feeding low-calorie hay may be a safer alternative to unrestricted grazing.

Avoid Grazing During High-Risk Times

Grass sugar and fructan levels are highly variable throughout the seasons and even throughout the day. NSC levels rise during daylight hours through photosynthesis and fall overnight as the plant uses the NSCs for growth. Therefore, grazing early in the morning when NSCs are at their lowest would be preferred to the afternoon. One exception for this is frosty mornings! When grass freezes over, the NSCs are not used for growth and accumulate to high levels in the plant, significantly increasing the risk of laminitis. When temperatures drop below 5˚C, limit grazing and offer conserved forage such as hay instead.

Additional Considerations- Vitamin E

Fresh grass is the best source of natural vitamin E for horses, a powerful antioxidant that supports immune function and muscle health. However, vitamin E levels in pasture decline during winter months, and horses on restricted grazing during spring and summer may not meet their requirements. In these cases, supplementing with natural vitamin E for horses can be beneficial year-round, particularly for those with limited pasture access, to support overall health and performance. For a natural, liquid vitamin E supplement with superior bioavailability, we recommend Kentucky Equine Research Nano-E.