An NSC diet refers to a feeding plan, most commonly for horses, that carefully manages the intake of Non-Structural Carbohydrates (NSC). This type of diet typically focuses on reducing the levels of sugar and starch in a horse's feed to support their health, especially for those prone to specific metabolic or digestive issues.
Understanding Non-Structural Carbohydrates (NSC)
NSC stands for Non-Structural Carbohydrates. In the context of animal nutrition, particularly for horses, NSC primarily refers to the combined levels of sugar and starch found in feedstuffs. These carbohydrates are rapidly digested in the small intestine and absorbed as glucose, providing a quick source of energy.
- Sugars: Simple carbohydrates that are readily available for absorption.
- Starches: Complex carbohydrates made up of many glucose units, which are broken down into sugars during digestion.
While performance horses rely on sugar, starch, and fat for energy, excessive amounts of NSC can be problematic for certain individuals. The topic of NSC comes up frequently when discussing low-carb, low-starch diets for horses.
What Constitutes an NSC Diet?
An NSC diet is a strategic feeding approach designed to control the amount of non-structural carbohydrates a horse consumes. The goal is often to provide a balanced diet that minimizes sugar and starch intake, thereby reducing the risk of conditions exacerbated by high NSC levels.
Who Benefits from an NSC Diet?
Horses with certain health conditions often thrive on or require a low-NSC diet. These include:
- Insulin Dysregulation (ID) / Equine Metabolic Syndrome (EMS): Horses with these conditions struggle to process sugars effectively, making low-NSC crucial for managing insulin levels.
- Laminitis: High NSC diets can trigger or worsen laminitis, a painful inflammatory condition of the hoof.
- Polysaccharide Storage Myopathy (PSSM): A muscle disorder where high starch intake can worsen symptoms.
- Cushing's Disease (PPID): While not directly caused by NSC, horses with PPID often have concurrent insulin dysregulation and benefit from a low-NSC diet.
- Gastric Ulcers: Some research suggests high starch intake might contribute to gastric ulcer development.
- "Hot" or Anxious Horses: Reducing rapidly digestible carbohydrates can sometimes help manage excitability in sensitive horses.
Key Principles of an NSC Diet
Implementing an NSC-controlled diet involves careful selection and management of all feed components:
- Forage-First Approach: The vast majority of a horse's diet should be high-quality, low-NSC forage.
- Minimal Concentrates: Commercial feeds, if used, should be specifically formulated as low-NSC.
- Strategic Grazing: Limiting or managing pasture access, especially during times when grass sugar levels are high.
- Supplement Scrutiny: Checking the NSC content of all supplements and treats.
Components of an NSC-Controlled Diet
Achieving a truly low-NSC diet requires attention to all feed sources.
Forage (Hay & Pasture)
Forage is the cornerstone of any horse's diet. For horses on an NSC diet, choosing the right forage is paramount.
- Hay Testing: The most reliable way to determine NSC content is to have your hay tested. Look for hay with a combined sugar (ESC - Ethanol Soluble Carbohydrates) and starch percentage of 10-12% or less for horses with severe sensitivities, or up to 15% for those with moderate needs.
- Hay Soaking: Soaking hay for 30-60 minutes can reduce its sugar content, though starch is less affected.
- Pasture Management: Grass can be very high in NSC, particularly in lush growth, during cold nights followed by sunny days, or in drought-stressed conditions.
- Restrict Grazing: Use grazing muzzles, limit turnout time, or provide dry lots.
- Monitor Conditions: Avoid turnout during peak NSC times (mid-morning to late afternoon on sunny days).
Commercial Feeds
Many commercial horse feeds are formulated to be low in NSC, often advertised as "low starch," "low sugar," or "safe for metabolic horses."
- Read Labels: Look for the guaranteed analysis that lists starch and sugar percentages. Aim for total NSC below 15%, and ideally under 10% for highly sensitive horses.
- Ingredients to Avoid/Limit: Traditional sweet feeds, oats, corn, barley, and molasses are typically high in NSC.
- Good Choices: Feeds that use ingredients like beet pulp, alfalfa meal, soy hulls, and specific forage products are generally lower in NSC.
| Feed Type/Component | Typical NSC Level | Common Ingredients |
|---|---|---|
| High NSC Feeds | High | Molasses, oats, corn, barley, wheat, sweet feeds |
| Moderate NSC Feeds | Moderate | Some fortified grains, standard pelleted feeds |
| Low NSC Feeds | Low | Beet pulp, alfalfa meal, soy hulls, specific low-NSC concentrates, unmolassed chaff |
Supplements and Treats
Even small amounts of NSC from supplements or treats can add up.
- Check Ingredients: Always review the ingredient list and guaranteed analysis of all supplements. Many palatable supplements use molasses or dextrose as binders or flavoring.
- Choose Wisely: Opt for natural, low-sugar treats like small pieces of hay, plain beet pulp, or tested low-NSC hay cubes.
The Importance of Managing NSC Levels
Managing NSC levels in a horse's diet is critical for preventing and controlling a range of health issues. While non-structural carbohydrates are essential energy sources for active horses, their controlled intake ensures digestive health, metabolic balance, and overall well-being, especially in susceptible individuals. By understanding what NSC entails and how to apply an NSC-controlled feeding strategy, horse owners can significantly improve their horse's quality of life.
