Equine Nutrition and Welfare: Evidence-Based Guide

Nutrition and Horse Welfare

Appropriate nutrition is foundational to equine welfare — both over- and under-nutrition cause significant welfare harm. Horses are physiologically adapted for continuous foraging of fibrous, low-calorie forage, and departures from this fundamental requirement drive many of the most common equine health problems.

The Forage Foundation

• Horses evolved on a diet of continuous trickle-feeding — 16-18 hours of grazing daily
• The digestive system is designed for constant forage intake; the gastric buffer capacity depends on saliva production during chewing
• Without continuous forage: gastric ulcers develop within hours to days; stereotypic behaviour (cribbing, weaving) develops over time
• Target: minimum 1.5-2% of body weight daily in hay/haylage (dry matter basis)

Common Nutritional Welfare Problems

• Obesity: Affects approximately 30-50% of horses in UK; risk factor for laminitis, EMS, and orthopaedic disease
• Gastric ulcers (EGUS): Affects up to 90% of racehorses and 58% of leisure horses; inadequate forage and stress are primary causes
• Laminitis from excess NSC: High non-structural carbohydrate intake causes insulin dysregulation and laminitis in susceptible horses
• Undernutrition: Body condition score below 2.5 indicates welfare-compromising nutritional inadequacy
• Vitamin and mineral deficiency: Selenium, copper, zinc, and vitamin E deficiencies cause muscle disease, immune failure, and developmental problems

Body Condition Scoring

Regular BCS assessment (1-9 scale) guides nutritional management:

• BCS 4-5: Ideal for most horses; ribs not visible but palpable with light pressure
• BCS 6+: Overweight; reduce caloric intake, increase exercise, test for EMS
• BCS 1-3: Underweight; increase forage and concentrate provision; investigate for disease

Feeding Management Principles

• Ad libitum hay or slow-feeder hay nets for most horses (restrict only for laminitis/EMS horses)
• Multiple small concentrate feeds rather than one large meal to reduce gastric acid exposure
• Gradual dietary changes (minimum 2 weeks transition) to prevent digestive upset and colic
• Fresh water available at all times (horses drink 25-50 litres daily)
• Forage analysis and supplement recommendations from a nutritionist for horses with specific health conditions

Key Takeaways

Horse nutrition is inseparable from welfare. Providing continuous, high-quality forage as the dietary foundation, monitoring body condition score regularly, and working with a nutritionist for horses with metabolic conditions are the most important nutritional welfare actions for any horse owner.