What Grass Has the Lowest NSC: A Comprehensive Guide
The most commonly cited grass with the lowest NSC (Non-Structural Carbohydrate) content is generally considered to be mature Bermudagrass. This makes it a popular choice for managing the diets of horses prone to metabolic issues.
Understanding Non-Structural Carbohydrates (NSC)
Non-Structural Carbohydrates (NSC) represent the easily digestible carbohydrates found in grasses. They primarily consist of sugars (simple sugars, fructose, glucose, sucrose) and starches. While NSC is a vital energy source for grazing animals like horses, excessive intake can trigger metabolic problems, particularly in insulin-resistant or laminitis-prone individuals. Therefore, knowing what grass has the lowest NSC is critical for many horse owners.
Why Low NSC Grass Matters
The implications of high NSC intake in susceptible animals are significant. Excess NSC leads to:
- Elevated blood glucose levels: triggering an insulin response.
- Insulin resistance: where cells become less responsive to insulin, leading to further glucose dysregulation.
- Laminitis: a painful and debilitating hoof condition often associated with insulin dysregulation and high NSC consumption.
- Obesity: contributes to overall metabolic dysfunction.
Choosing grasses with lower NSC values is a proactive measure in preventing these health issues. Managing what grass has the lowest NSC available to your horse is a crucial step in preventative care.
Factors Influencing NSC Levels
NSC levels in grasses aren’t static; they fluctuate based on various environmental and management factors:
- Time of Day: NSC levels are typically highest in the afternoon following photosynthesis. They’re usually lowest early in the morning, after respiration has consumed some of the carbohydrates produced during the day.
- Season: Cool-season grasses generally have higher NSC levels in spring and fall, when temperatures are cooler and growth is rapid. Warm-season grasses, like Bermudagrass, might see lower NSC levels overall, particularly when mature.
- Stress: Stressed plants, such as those experiencing drought or overgrazing, can accumulate NSC.
- Fertilization: Excessive nitrogen fertilization can lead to higher NSC levels.
- Maturity: Mature grass generally has lower NSC than rapidly growing, immature grass. This is because as the plant matures, more of the energy is diverted to structural components (fiber) rather than non-structural carbohydrates.
Comparing Common Grass Types
Here’s a general overview of NSC levels in some common grass types. Note that these are general ranges, and actual values will vary based on the factors mentioned above.
| Grass Type | NSC Range (%) | Notes |
|---|---|---|
| ———————- | ————- | ——————————————————————————————- |
| Ryegrass (Perennial) | 10-30 | Cool-season grass; typically higher NSC. |
| Timothy Grass | 10-25 | Cool-season grass; NSC can vary significantly depending on maturity. |
| Orchardgrass | 10-25 | Cool-season grass; NSC levels can increase during cool, sunny periods. |
| Fescue (Tall) | 8-20 | Cool-season grass; Some varieties are bred for lower NSC. |
| Bermudagrass | 5-15 | Warm-season grass; generally considered to have lower NSC, especially when mature. |
| Kentucky Bluegrass | 15-35 | Cool-season grass; Can have very high NSC content. |
Management Strategies for Lowering NSC Intake
Even if you don’t have access to grass with naturally low NSC, you can employ several strategies to reduce your animal’s NSC intake:
- Turnout Timing: Graze animals in the early morning when NSC levels are typically lowest.
- Grazing Muzzles: Use grazing muzzles to restrict grass intake.
- Hay Soaking: Soaking hay in water can leach out some of the water-soluble carbohydrates, effectively lowering the NSC content.
- Dry Lotting: Limit or eliminate grazing altogether, providing hay with a known NSC content.
- Pasture Management: Rotate pastures to prevent overgrazing and allow grasses to mature. Consider planting a mixed pasture with lower NSC grasses.
- Hay Analysis: Have your hay tested for NSC content to make informed feeding decisions.
Monitoring for Metabolic Issues
Regular monitoring for signs of metabolic issues is crucial, especially when grazing. Watch for:
- Weight gain or loss
- Insulin resistance (cresty neck, fat pads)
- Laminitis (heat in the hooves, reluctance to move)
- Elevated blood glucose or insulin levels
Consult with your veterinarian for appropriate diagnostic testing and management strategies.
Frequently Asked Questions (FAQs)
What factors contribute to NSC fluctuations in grass?
NSC levels fluctuate due to several factors, including time of day, season, plant stress, fertilization practices, and the grass’s maturity stage. Understanding these factors is key to managing grazing and mitigating NSC intake.
Is Bermudagrass always the best choice for horses with metabolic issues?
While mature Bermudagrass is often cited as having low NSC, it’s not a universally perfect solution. Hay testing is always recommended, as NSC levels can vary, and some horses might still be sensitive even to low NSC grasses. Furthermore, some horses dislike the texture of Bermudagrass.
How does hay soaking affect NSC levels?
Soaking hay in water can significantly reduce NSC levels by leaching out water-soluble carbohydrates. However, the effectiveness varies depending on soaking time, water temperature, and the type of hay. Discard the soak water after use, as it will be rich in sugars.
What is the ideal NSC range for a horse with insulin resistance?
There is no universally “ideal” NSC range, as individual sensitivity varies. However, many veterinarians recommend aiming for a total diet with an NSC content below 10%, and some horses may need even lower levels.
Can overgrazing affect NSC levels in pasture grasses?
Overgrazing stresses plants, leading to NSC accumulation as a defense mechanism. It also prevents grasses from maturing, increasing the proportion of rapidly growing, high-NSC shoots.
What are the signs of laminitis in horses?
Signs of laminitis include heat in the hooves, digital pulses, reluctance to move, a “sawhorse” stance, and, in chronic cases, rotation or sinking of the coffin bone.
Is all Bermudagrass the same in terms of NSC content?
No, different varieties of Bermudagrass can have varying NSC levels. Also, management practices play a critical role. Hay testing is essential to determine the actual NSC content of the hay you are feeding.
How often should I have my hay tested for NSC?
Hay should be tested for NSC every time you get a new batch. NSC levels can vary significantly between cuttings and even between different areas of the same field.
Besides grass, what other feeds can contribute to high NSC intake?
Grains (oats, corn, barley), molasses, and some commercial feeds can be high in NSC. Always read feed labels carefully and choose options with low NSC levels for susceptible animals.
Are there supplements that can help manage NSC levels in horses?
Some supplements claim to support insulin sensitivity and glucose metabolism, potentially helping to mitigate the effects of high NSC intake. However, consult with your veterinarian before using any supplements.
How does maturity affect the NSC content of grass hay?
As grass hay matures, the proportion of structural carbohydrates (fiber) increases, while the proportion of non-structural carbohydrates (sugars and starches) decreases. Therefore, more mature hay generally has lower NSC.
What steps can I take to ensure my horse’s pasture has grass with the lowest NSC?
Selectively planting grass with low NSC content (varieties of Bermudagrass or others that have been bred to be low in NSC), practicing good pasture management to promote maturity of the grasses, and regularly testing the grasses are all important steps in ensuring your horse’s pasture has grass with the lowest NSC.