NSC Values in Horse Feeds (Low-Sugar Reference Chart)
A reference chart of typical NSC percentages by feed type, with the under 10 to 12 percent target for PPID and EMS horses, plus how to test hay and lower sugar.
Quick answer: NSC (non-structural carbohydrates) is the sugar plus starch in a feed, expressed as a percent. For horses with PPID, EMS, or insulin dysregulation, the widely used target is a total diet NSC below about 10 to 12 percent, and under 10 percent for the most sensitive horses. Forage is the biggest part of the diet, so testing hay matters most. The values in the chart below are typical ranges only; actual NSC varies by batch, cutting, and growing conditions, so use feed tags and forage testing to know your horse's real numbers.
Typical NSC Values by Feed Type
The chart below gives general, approximate NSC ranges for common feed categories. These are orientation figures, not guarantees: real NSC swings widely with growing conditions, cutting, species, processing, and batch. The only way to know a specific hay or feed is a forage analysis or the manufacturer's tested value. Treat this as a guide to which feeds tend to run high or low, then verify the actual product.
| Feed Type | Typical NSC Range (approx.) | Notes for Metabolic Horses |
|---|---|---|
| Mature grass hay | ~8 to 18% | Often a good base; test it, and soak if values run high |
| Soaked grass hay | Variable, reduced | Soaking leaches some sugars; reduction is inconsistent |
| Beet pulp (plain, rinsed) | ~low, often under 12% | A low-sugar fiber source; avoid molassed versions |
| Purpose-built low-NSC / ration balancer | ~under 12% | Formulated for metabolic horses; check the tag |
| Typical senior feed | Varies widely, ~10 to 20%+ | Not automatically safe; verify the specific product |
| Oats / plain grains | ~40 to 55%+ | High; generally unsuitable for metabolic horses |
| Corn | ~65 to 75%+ | Very high starch; avoid for at-risk horses |
| Sweet feed (molasses) | ~25 to 40%+ | High sugar and starch; avoid for metabolic horses |
| Lush / stressed pasture grass | Highly variable, can be high | NSC swings with sun, season, frost; a laminitis risk |
Notice how grains and sweet feeds sit far above the safe target, while mature grass hay, beet pulp, and purpose-built low-NSC products cluster near or below it. This is why metabolic horses are fed forage-first diets with low-sugar concentrates only as needed.
Why NSC Matters So Much
When a horse eats sugars and starches, they are digested into glucose, which raises blood sugar and triggers an insulin response. In a healthy horse this is fine. In a horse with PPID, EMS, or insulin dysregulation, the system overreacts, and persistently high insulin is strongly linked to laminitis, the painful and potentially crippling foot disease that is the biggest threat to these horses. Keeping NSC low keeps those glucose and insulin spikes small, which is the core of protecting an at-risk horse.
Forage First: Test Your Hay
Because forage makes up the bulk of a horse's diet, the NSC of the hay usually matters more than the concentrate. The trouble is that you cannot judge hay's sugar content by sight, smell, or color: it varies dramatically between cuttings, fields, species, and even harvest conditions. A forage analysis from a testing lab reports the sugars and starch so you know what you are actually feeding. For any metabolic horse, testing hay is one of the highest-value steps you can take.
If a hay tests higher than you would like, soaking it in clean water can leach out some sugars and lower NSC, though the reduction is variable and the soak water should be discarded. Soaking works best as a tune-up alongside choosing lower-sugar forage, not as a guaranteed fix.
The Pasture Problem
Grass deserves special caution. Pasture NSC rises with sunlight and can be highest in the afternoon and during cold, sunny weather or drought stress. For a horse with PPID or EMS, free access to high-sugar grass is a genuine laminitis risk. Tools to manage it include grazing muzzles, limited or early-morning turnout, dry lots, and restricting access during high-risk grass conditions. Your vet or an equine nutritionist can help you build a safe grazing plan.
Putting It Together
For a metabolic senior, aim for a whole-diet NSC under about 10 to 12 percent, built on tested low-sugar forage, with low-NSC concentrates or a ration balancer to fill nutritional gaps, and careful pasture management. Confirm the right target with your vet for your individual horse, since the safe level depends on how insulin-dysregulated the horse is. Low-NSC feeding, paired with PPID medication where needed and good weight control, is the foundation of keeping these horses sound.
Related Reading
- PPID ACTH Testing Chart - Diagnosing the condition that demands low-NSC feeding.
- Horse Feeding Chart by Weight - How much forage to feed.
- Horse Weight Estimation Chart - Estimating weight to ration feed correctly.
- Henneke Body Condition Score Chart - Scoring fat cover from 1 to 9.
This chart is educational and complements, but does not replace, your veterinarian or equine nutritionist. NSC ranges are approximate; test your forage and confirm targets for your horse.
Frequently Asked Questions
What is NSC in horse feed?
NSC stands for non-structural carbohydrates, the sugars and starches in a feed or forage that are readily digested into glucose. It is usually expressed as a percentage of the feed and calculated as water-soluble carbohydrates (or simple sugars) plus starch. NSC matters because high-sugar, high-starch diets cause large blood glucose and insulin spikes, which are dangerous for horses with PPID, equine metabolic syndrome (EMS), or insulin dysregulation, raising their risk of laminitis. Lower-NSC feeding is central to managing these horses.
What NSC level is safe for a laminitic or PPID horse?
For horses with PPID, EMS, or insulin dysregulation, the widely cited target is a total diet NSC below about 10 to 12 percent. Many vets and nutritionists aim for under 10 percent for the most sensitive or actively laminitic horses. This applies to the whole diet, especially the forage, which makes up the bulk of what a horse eats. Always confirm the right target with your vet, since the safe level depends on the individual horse's metabolic status.
How do I know the NSC content of my hay?
The only reliable way is to have the hay analyzed by a forage testing laboratory, because NSC varies enormously between cuttings, fields, grass species, and even time of day at harvest. You cannot judge NSC by looking at hay. A lab test reports water-soluble carbohydrates, starch, and ESC, from which NSC is calculated. For a metabolic horse, testing hay is one of the most valuable steps you can take, since forage is the largest part of the diet.
Does soaking hay lower NSC?
Yes, soaking hay in water can reduce its water-soluble carbohydrate content, lowering NSC, because some sugars leach out into the water. The reduction is variable and not guaranteed to bring a high-sugar hay into a safe range, so it works best alongside testing rather than as a blind fix. Soaking also leaches minerals and must be done with clean water and the soak water discarded. For a metabolic horse, soaking is a useful tool but not a substitute for choosing lower-NSC forage.
Are senior feeds low in NSC?
Not automatically. Senior feeds are formulated to be easy to chew and digest, often with added fat and fiber, but their NSC varies widely by product. Some senior feeds are relatively high in sugar and starch, while others are specifically formulated as low-NSC. If your senior also has PPID or EMS, you must check the guaranteed analysis or contact the manufacturer for the NSC value rather than assuming a senior feed is safe. Many low-NSC senior and ration-balancer options exist.
What feeds are naturally low in NSC?
Generally, mature grass hays, products based on beet pulp and soy hulls, added fat, and purpose-formulated low-NSC feeds and ration balancers tend toward the lower end. Higher-NSC feeds include sweet feeds with molasses, grains like oats, corn, and barley, and lush spring or stressed pasture grass. Because actual values vary by product and batch, use feed tags, manufacturer data, and forage testing rather than assumptions. A vet or equine nutritionist can help you build a low-NSC diet.
Why is pasture grass a concern for metabolic horses?
Pasture grass can be surprisingly high in sugar, and its NSC swings with the season, time of day, sunlight, and stress from frost or drought. Sugars build up in sunny conditions and can be highest in the afternoon and during cold, sunny spells. For a horse with PPID or EMS, unrestricted grazing on high-sugar grass is a real laminitis risk. Strategies include grazing muzzles, limited turnout times, dry lots, and grazing in the early morning when sugars tend to be lower.
Need more help with your senior horse?
Browse our guides by topic to find practical solutions.
Wellness Planner: $39