Hay is one of the most fundamental components of a horse’s diet — the dried grass or legume forage that forms the backbone of equine nutrition across every season and discipline. Understanding hay types, quality indicators, and feeding practices is essential knowledge for anyone responsible for a horse’s care.
What Is Hay?
Hay is grass, legumes, or other plant material that has been cut, dried, and stored for use as animal feed. For horses, it serves as the primary source of fibre, which is critical for maintaining healthy gut motility and preventing conditions such as colic and laminitis. Most horses should consume between 1.5% and 2.5% of their body weight in forage daily, the majority of which comes from hay when grazing is limited.
Common Types of Hay
Grass hays include timothy, meadow hay, orchard grass, and ryegrass. These are generally lower in calories and protein, making them suitable for good-doers, horses in light work, or those prone to weight gain. Legume hays — primarily alfalfa (lucerne) and clover — are richer in protein, calcium, and energy, and are often fed to horses in hard work, breeding mares, or youngstock with higher nutritional demands.
Mixed hays combine grasses and legumes and are widely used in the UK as a practical compromise between palatability and nutritional value.
How to Assess Hay Quality
Good hay should smell sweet and slightly earthy — never musty or fermented. It should be free of dust, mould, and visible foreign material such as weeds or debris. Colour varies by type: good meadow hay is typically light green to golden, while overly brown or bleached hay has often been rained on after cutting and lost nutritional value. For a precise breakdown, a laboratory forage analysis will give you exact protein, sugar (NSC), and fibre levels — particularly valuable for horses with metabolic conditions such as EMS or PPID.
The British Horse Society provides guidance on hay and forage management as part of its horse welfare resources: www.bhs.org.uk
Hay vs. Haylage
Haylage is partially wilted and fermented forage, with a higher moisture content than hay (typically 30–50% dry matter). It is less dusty than hay, making it beneficial for horses with respiratory conditions such as RAO (recurrent airway obstruction). However, haylage is generally higher in energy and fermentable sugars than equivalent dry hay, so rations should be adjusted accordingly. See also: haylage.
Practical Feeding Tips
Always introduce a new batch of hay gradually to avoid digestive upset. Store hay off the ground on pallets in a well-ventilated, dry space to prevent mould formation. Soaking hay reduces dust and lowers water-soluble carbohydrates (sugar), which is why it is used for horses with respiratory issues or those prone to laminitis. The sugar loss varies widely, so no fixed soak time makes hay safe: UK hays soaked for up to 16 hours lost an average of 27% of their water-soluble carbohydrate (range 6% to 54%), and seven were still above the 100 g/kg dry matter ceiling suggested for laminitic animals afterwards (Longland and colleagues, 2011). For a laminitis-prone horse, have the forage analysed. Soaking can also leach out other nutrients. Slow-feeder nets extend eating time and more closely mimic natural trickle-feeding behaviour, reducing boredom and the risk of stable vices.
For horses on a forage-based diet, see also: forage and hard feed.
Frequently Asked Questions
How much hay does a horse need per day?
Most horses need approximately 1.5–2.5% of their body weight in forage daily. For a 500 kg horse, that translates to 7.5–12.5 kg of hay per day. Horses in hard work, youngstock, or those in poor condition may need the higher end of this range or additional concentrate feed.
Is it safe to feed dusty hay to horses?
Dusty hay should be avoided, particularly for horses with respiratory issues. Dust contains fungal spores that can trigger or worsen conditions such as RAO (heaves). Soaking or steaming hay before feeding significantly reduces dust and spore content. If hay quality is consistently poor, haylage or steamed hay may be more suitable alternatives.
What is the difference between first-cut and second-cut hay?
First-cut hay is harvested early in the growing season and tends to be coarser in texture with more stem. Second-cut hay, taken later in the year, is generally softer, leafier, and higher in protein and energy. Neither is inherently superior — the right choice depends on your horse’s workload, metabolic health, and individual nutritional requirements.