ASK THE EXPERT – HOW TO READ A HAY ANALYSIS
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When it comes to feeding performance horses, forage isn’t just filler; it’s fuel. Any information about the quality of hay we are feeding is thus invaluable and can tell us about the true nutritional value of what our horses are eating and how balanced their overall diet is.
This kind of information requires a hay analysis, which, whilst not readily available to owners in South Africa, has been performed by several feed companies and vets. The information they can give us about the kind of hay in our area or the general trends and characteristics of the hay we are using is something many of us don’t know we can ask about, but should.
To help demystify lab reports and understand what a hay analysis (often filled with numbers and acronyms) can tell us, once acquired from a vet, equine nutritionist or feed company, we asked an equine nutrition expert to break it down.
Why hay analysis matters
Forage makes up the majority of a horse’s diet, so understanding what’s in your hay allows you to make informed decisions about concentrates, supplements, and balancers. Analysing hay can reveal if your horse is getting enough protein, energy, and minerals, or if their feed plan is leaving nutritional gaps.
It’s particularly vital for horses with specific needs: those prone to laminitis, metabolic disorders, ulcers, or intense competition workloads.
Key components to look for
- Dry Matter (DM)
Dry matter reflects the portion of hay excluding moisture usually around 85–90% for good-quality hay. It’s the value used to compare different feeds fairly.
- Crude Protein (CP)
Protein supports muscle repair, growth, and overall health.
- Good hay for performance horses: 10–14% CP
- Maintenance or easy keepers: 7–10% CP
Low protein may lead to poor topline and slow recovery, while excessive levels can stress the kidneys and lead to dehydration.
- Fibre: NDF and ADF
- Neutral Detergent Fibre (NDF) indicates how ‘filling’ a hay is, i.e. how much a horse can eat before feeling full. Higher NDF means more structural fibre and less intake.
- Acid Detergent Fibre (ADF) measures indigestible components like lignin. The lower the ADF, the more digestible the hay.
Ideal range:
- NDF: 50–65%
- ADF: 30–40%
- Non-Structural Carbohydrates (NSC)
NSC includes sugars and starches so is crucial for energy but risky for horses prone to laminitis or ulcers.
- Low NSC (<10%): safe for metabolic or ulcer-prone horses
- Moderate NSC (10–12%): ideal for most riding horses
- High NSC (>15%): suitable only for hard-working sporthorses under careful management
- Minerals and the Ca:P ratio
Calcium (Ca) and phosphorus (P) are essential for bone health and muscle function. The correct Ca:P ratio should be 1.5–2:1. Imbalance can hinder bone strength and performance.
Also check magnesium, potassium, and trace minerals (zinc, copper, selenium) as deficiencies are common in local hays.
Science simplified: Decoding hay fibre
When you see ADF and NDF on a hay analysis, don’t panic; they’re just two ways of measuring fibre quality. Together, they tell you how digestible your hay is and how much energy your horse can get from it.
NDF – Neutral Detergent Fibre
What it measures: The total bulk of the plant’s cell wall, cellulose, hemicellulose and lignin.
What it means: The higher the NDF, the more fibrous (and filling) the hay. Horses can’t digest this fibre directly; it’s fermented by microbes in the hindgut.
In practice:
- Low NDF (below ~40%) – softer, leafier hay that’s easy to digest and higher in energy.
- Moderate NDF (40–55%) – ideal balance for most performance horses.
- High NDF (above ~60%) – coarse hay that fills the gut quickly but offers less energy.
Use it to: Match hay type to your horse’s needs, i.e. high-NDF for easy keepers, low-NDF for hard-working or hard-keeping horses.
ADF – Acid Detergent Fibre
What it measures: The least digestible portion of the fibre, cellulose and lignin (the woody, structural parts of plants).
What it means: The higher the ADF, the less your horse can actually digest and convert to energy.
In practice:
- Low ADF (below ~30%) – high-quality, nutrient-dense hay with good digestibility.
- Moderate ADF (30–40%) – acceptable for most adult horses.
- High ADF (above ~45%) – mature, stemmy hay that’s lower in calories and harder to break down.
Use it to: Judge hay quality at a glance. A low ADF number means better digestibility and more nutritional value per kilo.
NDF and ADF = digestibility and fill
Think of it this way:
- NDF tells you how much hay a horse can eat before feeling full.
- ADF tells you how much energy they’ll get from what they’ve eaten.
Together, they’re the best indicators of hay quality and suitability, even more than protein alone.
Science simplified: What ‘NSC’ really means
When you see NSC (Non-Structural Carbohydrates) on a hay or feed label, it refers to the sugars and starches your horse can quickly digest for energy. Unlike the slow-fermenting fibres in forage, NSCs deliver fast fuel, but too much can disrupt the gut and trigger metabolic or gastric issues.
Why NSC matters
Sugars and starches are digested in the small intestine and absorbed as glucose. In hard-working horses, this fuels performance. However, in horses with metabolic problems, ulcers, or a risk of laminitis, high NSC levels can overwhelm the system, leading to blood sugar spikes, hindgut acidosis, or inflammation.
Interpreting NSC values
| NSC range | What it means | Best for |
| Low (<10%) | Safe for horses with metabolic issues (EMS, PPID) or prone to ulcers and laminitis. | Sensitive or resting horses |
| Moderate (10–12%) | Balanced energy level for most riding and competition horses. | General performance or leisure horses |
| High (>15%) | High-energy fuel for elite athletes — but requires careful feed management and monitoring. | Hard-working sporthorses only |
Science behind the numbers
NSC is calculated as the sum of simple sugars + starch, sometimes including fructans (complex plant sugars). It’s best measured through laboratory analysis, though most feed companies can provide approximate figures for their products.
In practice
If your horse is prone to ulcers, metabolic syndrome, or ‘hot’ behaviour, choose hay or feed with lower NSC and spread meals out to stabilise gut pH and blood sugar.
For intense work, moderate NSC can support muscle glycogen replenishment, provided the diet still includes ample fibre and balanced electrolytes.
The South African reality
In South Africa, hay analysis isn’t as straightforward as it might sound. Few independent laboratories routinely offer equine forage testing, and most horse owners don’t have easy access to facilities that can interpret results in an equine context.
However, several major feed companies and equine nutrition consultancies do offer hay testing services, either through partnerships with agricultural labs or as part of their diet-formulation programmes. While this may not be practical for every horse owner, it can be invaluable for studs, performance yards, or riders managing high-level competition horses, where precision feeding can have a tangible impact on performance and recovery.
For everyday horse owners, the key takeaway is awareness: hay quality and composition can vary dramatically depending on grass species, cutting stage, and region. Even without lab testing, choosing hay that’s leafy, soft, and sweet-smelling, and avoiding overly coarse or stemmy types, remains the best starting point.
Interpreting the results
Once you know the nutrient profile of your hay, you can choose the right balancer or concentrate to fill any gaps. For instance:
- Low protein? Add a legume hay or high-protein balancer.
- High NSC? Reduce concentrates or add beet pulp.
- Low calcium? Supplement or mix with lucerne.
Always consult an equine nutritionist to balance the full diet.
A note on grazing
A hay analysis gives invaluable data, but it only tells part of the nutritional story in terms of forage. For many South African horses, pasture makes up a large portion of their diet – and grass can vary even more than hay in energy, sugar, and fibre content.
The same principles that apply to hay analysis also shape pasture quality. As grass matures, its fibre levels (ADF and NDF) rise, while crude protein (CP) and digestibility decline. Early, leafy growth provides more energy and protein but can also be higher in sugars. Mature, stemmy grass offers bulk and gut fill, yet fewer calories, which is ideal for good doers or horses needing weight control.
On top of this, fresh grass is dynamic. Its non-structural carbohydrates (NSC), the simple sugars and starches that provide quick energy, fluctuate throughout the day. During sunny hours, photosynthesis drives sugar production, peaking in the late afternoon; overnight, those sugars are used for growth, so levels fall again by morning. This means that a horse grazing in the cool, early hours will consume significantly less sugar than one turned out on the same pasture in the afternoon.
Season and climate add another layer. Irrigated summer pastures or post-rain regrowth often contain high NSC levels – sometimes over 20% – increasing the risk of laminitis or metabolic flare-ups in sensitive horses. Conversely, dry winter veld or mature kikuyu can be very high in fibre (NDF > 65%) and low in protein, meaning horses may require additional energy and amino acids from concentrates.
Because forage testing of paddocks isn’t common or practical in South Africa, owners need to rely on observation: watch how your horse’s weight, energy, and droppings change with the season, and adjust concentrates accordingly. For metabolic, ulcer-prone, or overweight horses, consider nighttime turnout, grazing muzzles, or restricted access to rich grass.
In short, understanding pasture nutrition uses the same logic as reading a hay report, just without the laboratory numbers. The goal is balance: enough fibre to sustain gut health, enough protein to support muscle and topline, and sugar levels appropriate to your horse’s needs.
DIY hay evaluation: A practical guide for South African riders
If lab testing isn’t accessible, you can still assess hay quality using your senses. While this won’t replace a nutritional analysis, it can help you make smarter choices at the feed store or when buying bales from different suppliers.
Look
- Colour: Bright green or golden hues suggest good curing and vitamin preservation. Grey or brown hay may indicate overheating, rain damage, or age.
- Leafiness: The more leaves, the higher the nutrient content. Stemmy, coarse hay is lower in energy and harder to digest.
- Uniformity: A consistent texture and cut across the bale usually means even drying and less chance of mould.
Smell
- Sweet and fresh: The best hay has a clean, grassy aroma.
- Musty or sour: Signs of mould or bacterial spoilage – don’t feed this to horses, even in small amounts.
Touch
- Soft, flexible stems: Indicate early cutting, which is richer in protein and easier to chew.
- Hard, brittle stalks: Mean the grass was cut too late and has lower digestibility.
Check for contaminants
- Watch for weeds, sticks, or foreign material.
- Inspect for dust clouds. To do this, shake a small flake; excessive dust suggests mould spores or poor storage.
- Always avoid hay with any black or white mould spots.
Quick tip
If you regularly feed hay from different regions or suppliers, introduce new hay gradually over seven to ten days to protect gut microbes and reduce the risk of colic.
Bottom line
Understanding your hay analysis, or at least beginning to understand what it means, can help you to understand your horse’s nutrition and its balance. When combined with consideration of grazing quality and the nutritional values of the concentrate you feed, you can begin to ensure your horse’s diet truly supports their work, temperament, and long-term health.