Introduction to Equine Nutrition
A horse's digestive system is designed for continuous grazing on high-fiber forages. A diet based on affordable natural forage—primarily grass hay or pasture—provides the foundation for optimal health, digestion, and behavior. This guide explains how to use hay, pasture, and minimal supplements to meet your horse's nutritional needs without expensive commercial feeds.
Types of Natural Forage
Grass Hay
Grass hay (timothy, orchard grass, brome, Bermuda) is low in calories and sugar, making it ideal for most horses. Feed 1.5–2% of body weight daily (e.g., 15–20 lb for a 1,000 lb horse).
Legume Hay
Alfalfa or clover hay is higher in protein and calcium. Use sparingly for growing, lactating, or hardworking horses, as excess can cause obesity or metabolic issues. Mix with grass hay if needed.
Pasture Grazing
Turnout on good-quality pasture reduces hay costs. Monitor sugar content (higher in spring and fall; graze during early morning or late evening). Introduce gradually to prevent laminitis.
Feeding Frequency and Amounts
Horses should have access to forage for at least 16–20 hours per day. Divide hay into 2–4 feedings to mimic natural grazing and reduce boredom. Provide 1.5–2% of ideal body weight in forage daily. Adjust for activity level: idle horses need less; performance horses may need additional energy from concentrates.
Essential Nutrients from Forage
- Fiber: Essential for hindgut fermentation; slows digestion and prevents colic.
- Protein: Mature grass hay (8–10% crude protein) meets most needs; growing horses require 12–16%.
- Vitamins: Forage provides A, D (sunlight), and E. Balanced hay may lack vitamin E; supplement if hay is stored >6 months.
- Minerals: Calcium and phosphorus ratio should be 1.5–2:1. Avoid excess phosphorus (found in grains). Most hay is low in salt, copper, zinc, and selenium.
Hazardous Foods and Plants
Never feed: moldy hay (respiratory issues, colic); grain overload (laminitis, colic); toxic plants (ragwort, bracken fern, yew, oak leaves, red maple). Also avoid: fruit pits (cyanide), grass clippings (rapid fermentation), and stale water.
Water Requirements
Provide 5–10 gallons of clean water per day for a 1,000 lb horse; more in hot weather or lactation. Check water intake; decreased drinking may indicate illness or poor palatability.
When to Supplement
Most horses on good forage do not need concentrates. Supplement with a balanced vitamin/mineral premix if hay lacks trace minerals (common in many regions). Salt (free-choice) is essential. Supplement vitamin E if hay is stored >6 months. Probiotics may help after antibiotic use or stress.
Feeding by Age and Workload
Adjust forage and supplement ratios:
| Category | Forage (1,000 lb horse) | Additions |
|---|---|---|
| Idle (mature) | 15 lb grass hay | Mineral salt, maybe vitamin E |
| Light work | 15–20 lb grass hay | May need low-starch balancer |
| Intense work | 15–20 lb hay + alfalfa | Fat supplement (rice bran) if needed |
| Growing foal (6 months) | Hay + pasture | 12–16% protein ration if forage low |
| Senior (20+ years) | Soft, high-quality hay | Senior feed if teeth poor; extra hay pellets |
Signs of Good vs. Poor Diet
Good diet: shiny coat, calm demeanor, consistent manure (formed but not hard), healthy hoof growth, ideal body condition (ribs easily felt but not visible).
Poor diet (excess energy): obesity, cresty neck, laminitis, excitability, loose manure.
Poor diet (deficiency): dull coat, weight loss, poor muscle tone, odd behaviors (wood chewing, coprophagy), weak hoof walls, slow growth in foals.
Conclusion
A natural forage-based diet is economical and biologically appropriate for horses. Prioritize high-quality grass hay, manage pasture intake, and supplement only as needed. Regularly evaluate body condition and consult your veterinarian to adjust feeding for your horse's specific needs.