Understanding a Mustang's Nutritional Background
Wild Mustangs are adapted to thrive on sparse, varied range grasses — often low in sugars and rich in fiber. Their digestive systems are finely tuned to extract nutrition from forage that most domestic horses might turn their nose up at. This background has important implications when you bring a Mustang into a domestic setting: overfeeding, especially with rich feeds, is one of the most common and dangerous mistakes new owners make.
The Foundation: Forage First
For any horse, but especially Mustangs, forage should form the backbone of the diet. This means:
- Grass hay: Timothy, orchard grass, or native grass hay are excellent choices. Aim for grass hay as the primary roughage source.
- Pasture: Access to well-managed pasture is beneficial, but be cautious in spring when grass sugar levels spike — this can trigger laminitis in horses that aren't accustomed to rich forage.
- Quantity: A general guideline is 1.5–2% of body weight in forage per day. Weigh your hay — most people significantly underestimate portion sizes.
The Transition Period: Go Slowly
When a newly adopted Mustang arrives, its gut microbiome is adapted to the plants of its home range. Suddenly switching to domestic hay can cause digestive upset, colic, or diarrhea. Follow these principles during the first few weeks:
- Start with free-choice grass hay — not alfalfa
- Avoid grain entirely for the first several weeks unless directed by a vet
- Introduce any new feed gradually over 10–14 days minimum
- Ensure constant access to clean, fresh water
- Provide a plain white salt block — electrolyte balance is critical
Should You Feed Grain or Concentrates?
Most Mustangs in light to moderate work do not require grain. Their efficient metabolisms mean they can easily maintain weight — and even become overweight — on forage alone. However, there are situations where a concentrate may be appropriate:
- Horses in heavy training or competitive work with high caloric needs
- Senior horses that struggle to maintain weight on hay alone
- Horses recovering from illness or injury under veterinary supervision
- Underweight rescue horses needing careful, slow refeeding
If you do use a concentrate, choose a low-starch, low-sugar formulation designed for easy keepers. Avoid sweet feeds.
Important Minerals and Supplements
Mineral needs vary significantly by region, as local soil and forage mineral content differs widely. A hay analysis from your local extension office can be invaluable. Common considerations include:
| Mineral / Supplement | Why It Matters | Notes |
|---|---|---|
| Salt | Electrolyte balance, hydration | Free-choice block or loose salt year-round |
| Selenium | Muscle function, immune health | Deficient in many regions — test before supplementing |
| Vitamin E | Antioxidant, muscle health | Often low in hay-only diets (fresh grass is the natural source) |
| Magnesium | Metabolic function, calm demeanor | Worth discussing with a vet if horse is "hot" or grass-heavy diet |
Watch for These Warning Signs
Monitor your Mustang's body condition regularly using a standardized body condition score (BCS) system. Aim for a score of 4–6 on the standard 9-point scale. Be alert to:
- Cresty neck or fat pads (signs of metabolic issues / too-rich diet)
- Ribs showing prominently (underweight — increase forage)
- Dull coat (possible mineral deficiency)
- Changes in manure consistency (digestive upset — review recent feed changes)
Work with a Professional
If you're unsure about your Mustang's specific nutritional needs, don't guess. A consultation with an equine veterinarian or certified equine nutritionist — especially in the first year of ownership — is well worth the investment. The cost of a professional consultation is far less than treating a nutrition-related illness.