Forage, or roughage, is more than just filler in a horse’s diet: It’s the foundation of equine health. The terms ‘roughage’ and ‘forage’ both refer to the plant-based feeds consumed by horses, whether fresh or conserved. These feeds may include pasture, hay, chaff, chaff cubes, haylage, baleage, or silage.
Horses evolved as continuous grazers, and their digestive systems rely on a steady supply of fibrous plant material to function properly.
This article explores why forage is vital, what happens when it is lacking, and how you can ensure your horse receives the right amount and quality.
Why horses need constant access to forage
Horses in the wild graze for 16 to 18 hours a day. Their digestive system is designed for this near-constant intake of low-energy, fibrous food. Unlike carnivores or omnivores, horses are hindgut fermenters, meaning their digestive efficiency and gut health rely heavily on a continuous flow of forage through the large intestine. When horses do not have access to forage for several hours, their digestive function begins to suffer, increasing the risk of health complications.
The act of chewing is just as important as the forage itself. Chewing stimulates saliva production, which helps buffer the acidity in the stomach. Since horses secrete gastric acid continuously, this buffering process is essential to prevent ulcers. In fact, studies show that horses deprived of forage for longer than four to six hours are significantly more likely to develop gastric lesions.
Furthermore, access to forage supports mental wellbeing. Horses are highly intelligent, social animals with a need for mental stimulation. Forage satisfies the need to chew, offers a sense of routine and stability, and allows the horse to express natural foraging behaviour. Horses that lack sufficient forage often exhibit signs of stress, such as pawing, weaving, or aggressive behaviour during feeding.
In performance horses, consistent forage availability can improve concentration, recovery time, and even hydration status. Long-stem forage also supports respiratory health by encouraging breathing and reducing the risk of stable vices linked to boredom. Simply put, forage is not just nutrition; it’s comfort, structure, and medicine for the equine digestive and psychological systems.
What happens when horses lack fibre?
Fibre is vital for keeping a horse’s digestive tract functioning smoothly. When horses are deprived of sufficient forage (roughage), the first system to suffer is the gut. Without the necessary bulk to stimulate intestinal movement, food slows down, increasing the risk of impaction colic. This condition can be life-threatening and costly to treat.
A low-fibre diet also leads to imbalances in the microbial population in the hindgut, where fermentation of fibre occurs. These microbial shifts can trigger excess gas, acidity, or inflammation, all of which can result in colic or laminitis. Horses on high-concentrate, low-forage diets are especially prone to these problems, as starches and sugars overload the system, leading to acidic fermentation and toxin release.
Behaviourally, horses that lack chewing time may exhibit oral stereotypies such as crib-biting, wood-chewing, or even coprophagy (eating manure). These are not simply bad habits but coping mechanisms for unmet dietary and behavioural needs. Over time, such behaviours can lead to dental wear, weight loss, and chronic stress.
Moreover, insufficient fibre means insufficient saliva production. Saliva is alkaline and helps buffer gastric acid, so reduced chewing translates directly into increased ulcer risk. In growing horses, broodmares, and seniors, chronic fibre deficiency can also impair immunity, fertility, and musculoskeletal development.
How much forage does your horse need daily?
The right amount of forage is not one-size-fits-all. However, a widely accepted guideline is that a horse should consume between 1.5% and 2.5% of its body weight in forage daily. For an average 500 kg horse, this translates to 7.5 to 12.5 kg of hay or grass dry matter. This range depends on factors such as metabolism, age, workload, climate, and body condition.
Adjusting forage to individual needs
Robust horses (ponies or native breeds) may maintain condition on 1.5% of body weight, while horses with increased needs, lactating mares, or performance horses may require closer to 2.5%. It’s also crucial to account for forage dry matter content: fresh grass is typically 70-80% water, so pasture-only diets must provide enough volume to meet dry matter requirements.
Monitoring your horse’s body condition score (BCS) regularly is a practical way to ensure your forage plan is working. If your horse is gaining too much weight, consider shifting to lower-energy forage such as mature hay or straw-based blends. If weight loss is a concern, switch to higher-quality forage with more leaf content and potentially add fibre supplements like beet pulp.
Horses with dental issues or older horses with reduced chewing efficiency may struggle with long-stem forage. In these cases hay replacers such as chopped hay, soaked hay pellets, or haylage can ensure sufficient fibre intake without compromising digestibility or comfort,
Tips for feeding hay, grass, and alternatives
Feeding forage effectively means considering not just the quantity, but the quality and suitability of the source. Poor-quality hay can do more harm than good, leading to respiratory issues, impactions, or even mycotoxin exposure.
Choosing the right forage
When choosing hay, look for a clean, fresh smell, minimal dust, and absence of mould. Colour alone is not a reliable indicator of quality; some highly nutritious hay may appear bleached from sun exposure. Testing hay for its nutritional profile (protein, sugars, fibre content) allows more precise ration balancing.
Grass is an excellent source of forage, but not all pastures are created equal. Overgrazed or poorly maintained paddocks may lack nutritional diversity and increase the risk of parasite exposure. Implementing a rotational grazing system, harrowing, reseeding, and proper manure management can dramatically improve forage quality over time.
Forage alternatives and feeding strategies
In regions with limited hay availability, or during drought or supply chain shortages, alternatives like haylage, silage, straw, or commercial high-fibre feeds become essential. Each comes with pros and cons. Haylage is often more palatable and less dusty but must be properly stored to prevent spoilage. Straw can extend chewing time but should not be the sole forage source due to its low digestibility.
Feeding strategies should also match the horse’s needs and lifestyle. Slow feeders, small-holed hay nets, and ground-level racks can extend feeding time, reduce waste, and mimic natural grazing patterns. Horses on box rest or limited turnout benefit greatly from these tools. Soaking hay for 30-60 minutes reduces water-soluble carbohydrates (WSC), making it safer for horses with EMS or Cushing.
Combining different forage types can prevent boredom and support a more balanced intake. A mix of hay and haylage, or chopped forage with beet pulp, offers textural and nutritional variety. Feeding little and often is the golden rule, ensuring constant gut fill and preventing spikes in insulin, acid, or stress.
Conclusion
Forage, or roughage, are not optional add-ons to a horse’s diet but they are essential building blocks of health. Every system in a horse’s body, from digestion to mental wellbeing, relies on the constant intake of high-quality fibre. Without adequate forage, horses suffer physically and mentally. With the right knowledge and attention to forage quality, type, and quantity, horse owners can support longevity, reduce veterinary costs, and improve the quality of life for their animals.
Whether your horse is a retiree on the paddock, a performance athlete, or a family companion, forage must remain the cornerstone of its diet. It’s not just about feeding hay but it’s about feeding health, balance, and the horse’s natural instincts.