Hay Analysis Explained (September 2026) What the Numbers Mean

If you feed horses, you have probably wondered whether a hay analysis is worth the effort. The short answer is yes, especially if your horse has any metabolic concerns, weight issues, or performance demands. A hay analysis removes the guesswork from feeding and tells you exactly what your horse is getting in every flake.

I remember staring at my first hay analysis report and feeling completely lost. The columns of abbreviations, the percentages, the two sets of numbers for everything. It looked like a chemistry exam I was not prepared for. That experience is what led me to break down every number on a typical report so you do not have to feel that same confusion.

Whether you are managing a laminitic pony, an easy keeper, or a performance horse, understanding your hay analysis helps you make better feeding decisions. In this guide, I walk you through what each number means, which ones actually matter, and how to decide whether testing is worth it for your situation in 2026.

What Is a Hay Analysis and How Does It Work?

A hay analysis is a laboratory test that measures the specific nutrient content of your hay. Instead of guessing whether your hay is high in protein or sugar, you get actual numbers from a forage testing lab that tell you exactly what your horse is eating.

The process is straightforward. You collect samples from multiple bales using a tool called a hay corer or hay probe. You send those samples to a forage analysis laboratory, and within about a week, you receive a report showing protein levels, fiber content, sugar values, energy estimates, and mineral concentrations.

A basic hay analysis costs around $20 to $30. That single test can cover hundreds of bales from the same cutting and field. When you think about how much you spend on hay over a year, that $20 is one of the cheapest investments you can make in your horse’s nutrition.

The results typically come back as a one or two page report with two columns of numbers. One column shows nutrients on an as sampled basis, meaning the values include the moisture naturally present in the hay. The other column shows nutrients on a dry matter basis, which removes the water content and lets you compare different hay sources directly. I explain both columns in detail below because understanding the difference is critical for reading your results.

Most horse owners I talk to on forums like Chronicle of the Horse and r/Equestrian fall into one of two camps. Either they test religiously every time they get a new load of hay, or they have never tested at all because the results seem too confusing to interpret. My goal with this guide is to move you confidently into that first group.

As Sampled vs Dry Matter: Which Column Should You Read?

Every hay analysis report shows two columns for each nutrient, and this trips up more horse owners than anything else. Here is what you need to know.

The As Sampled column includes the natural moisture content of your hay. If your hay has 12% moisture, that water weight dilutes all the other nutrient values downward. The Dry Matter column strips out the water and reports nutrients as if the hay were 100% dry matter.

Always use the Dry Matter column when comparing hay from different sources, cuttings, or years. Because moisture levels vary from field to field and even bale to bale, the Dry Matter basis gives you an apples-to-apples comparison. Penn State Extension and University of Minnesota Extension both recommend using the dry matter column for all comparisons and ration balancing.

One important number to check in the As Sampled column is moisture content itself. Ideal moisture for horse hay runs between 10% and 15%. Hay with moisture above 18% to 20% is at risk for mold growth and bacterial spoilage. At extremely high moisture levels, hay can even generate enough heat through microbial activity to cause spontaneous combustion. I have seen barn fire reports linked back to improperly cured hay, so this is not just a theoretical concern.

Hay testing below 10% moisture is not dangerous, but it tends to be dusty and brittle. Very dry hay shatters when handled, creating respiratory irritants that can affect horses with heaves or respiratory sensitivities.

Key Nutrients on a Hay Analysis: What Each Number Means

This is where most horse owners get overwhelmed, so I am going to break down each nutrient one at a time. Once you understand what each abbreviation stands for and what the ideal range looks like, reading a hay analysis becomes second nature.

Crude Protein (CP)

Crude Protein measures the total protein content of your hay, including both true protein and non-protein nitrogen sources. For most mature idle horses, a CP value between 8% and 12% on a dry matter basis is adequate. Growing horses, broodmares in late gestation, and lactating mares need higher protein levels in the 12% to 16% range.

Is 14% protein in hay too high for horses? For most adult horses at maintenance level, 14% protein is perfectly fine and not dangerously high. The concern with excess protein is not toxicity but waste. The horse breaks down surplus protein and excretes the nitrogen as urea, which increases water intake and urine output. If you are feeding a mature idle horse 14% protein hay along with a high-protein concentrate feed, you are likely overfeeding protein without realizing it.

Legume hays like alfalfa typically test higher in crude protein, often 15% to 22% on a dry matter basis. Grass hays like timothy, orchardgrass, and bermudagrass generally run lower, around 6% to 12% CP depending on maturity at harvest.

Acid Detergent Fiber (ADF)

Acid Detergent Fiber measures the least digestible portions of the plant, primarily cellulose and lignin. Think of ADF as your digestibility indicator. Lower ADF values mean the hay is more digestible because it was harvested at an earlier growth stage when the plant was less mature and softer.

An ADF value below 35% on a dry matter basis indicates high quality, highly digestible hay. Values between 35% and 40% are considered moderate. Anything above 40% means the hay was harvested late, is quite mature, and will be harder for your horse to digest. Horses can still use high ADF hay for maintenance, but they will extract fewer nutrients from each pound.

I like to check ADF early when I read a report because it immediately tells me whether the hay was cut at the right time. A high ADF value explains why a horse might be losing condition on what looks like plenty of hay.

Neutral Detergent Fiber (NDF)

Neutral Detergent Fiber includes everything in ADF plus hemicellulose, giving you the total structural fiber content of the plant. NDF is your intake predictor. Higher NDF means more fill in the digestive tract and less voluntary intake by the horse.

NDF values below 40% indicate very palatable hay that horses will eat eagerly. Values between 40% and 50% represent good quality hay with normal intake levels. Once NDF climbs above 60%, horses tend to eat less of the hay voluntarily because it is bulky and less appealing.

For horses that need to lose weight, higher NDF hay can actually be helpful because it provides gut fill and satisfies the urge to chew without delivering excessive calories. For hard keepers or performance horses with high energy demands, you want lower NDF hay so the horse consumes more total nutrients.

The relationship between ADF and NDF tells you about overall forage quality. When both values are low, you have premium hay harvested at peak maturity. When both are high, the hay is overmature and best suited for maintenance animals or as a chew filler alongside better quality forage.

Non-Structural Carbohydrates (NSC)

NSC is the number most horse owners care about, and for good reason. Non-Structural Carbohydrates represent the sugars and starches in the hay, including fructans, glucose, fructose, and sucrose. For horses with laminitis, Equine Metabolic Syndrome (EMS), Pituitary Pars Intermedia Dysfunction (PPID), or insulin dysregulation, NSC is the single most important value on the entire report.

The commonly cited threshold for metabolic horses is an NSC value below 10% on a dry matter basis. Many equine nutritionists recommend keeping NSC under 12% for horses prone to laminitis. For healthy horses without metabolic concerns, NSC values up to 20% are generally not problematic.

Here is where things get nuanced. NSC is typically calculated as the sum of WSC plus starch, or in some lab reports, as NFC (non-fiber carbohydrates). Understanding the components helps you interpret the number more precisely.

Water Soluble Carbohydrates (WSC) and Ethanol Soluble Carbohydrates (ESC)

WSC measures all water-soluble sugars plus fructans. ESC measures only the simple sugars extracted by ethanol, which roughly corresponds to the sugars that cause an insulin response in the horse. The difference between WSC and ESC tells you how much fructan is present.

Fructans are a concern because they are fermented rapidly in the hindgut, potentially causing acidosis and triggering laminitis in susceptible horses. However, recent research suggests that the ESC value may be more clinically relevant for predicting insulin spikes than total NSC, since fructans are primarily fermented in the hindgut rather than absorbed as sugars in the small intestine.

For practical purposes, if your horse has EMS or a history of laminitis, pay close attention to both ESC and starch individually. Many nutritionists now recommend ESC plus starch below 10% for high-risk metabolic horses. If your lab report only gives you WSC and starch, you can calculate NSC as WSC plus starch.

I have seen forum discussions where horse owners get conflicting advice from veterinarians and nutritionists about whether to target NSC or ESC plus starch. The reality is that both matter, but if you have to choose one to monitor, ESC plus starch gives you the clearest picture of the insulin response risk.

Digestible Energy (DE)

Digestible Energy measures the caloric value of the hay, expressed in megacalories per kilogram (Mcal/kg) or megajoules per kilogram (MJ/kg). DE tells you how much usable energy your horse extracts from each unit of hay consumed.

A typical grass hay DE value ranges from 1.8 to 2.2 Mcal/kg on a dry matter basis. Legume hays tend to run higher, around 2.0 to 2.4 Mcal/kg, because they contain less fiber and more digestible nutrients per pound. Higher DE means fewer pounds of hay needed to meet your horse’s energy requirements.

For a 1,000-pound horse at maintenance, daily DE requirements run around 16 to 17 Mcal. If your hay tests at 2.0 Mcal/kg on a dry matter basis, you can calculate how many pounds of hay your horse needs to meet that energy target. This is where a hay analysis becomes truly powerful for ration balancing.

Performance horses, growing horses, and lactating mares all have higher DE requirements. Knowing your hay’s DE value lets you determine how much additional energy you need from concentrates or supplements to fill the gap.

Minerals: Calcium (Ca) and Phosphorus (P)

Most hay analysis reports include calcium and phosphorus values, along with the calcium-to-phosphorus ratio. Horses require a Ca:P ratio of at least 1:1, with an ideal range between 1.5:1 and 2:1 for adult horses. Growing horses and broodmares benefit from a ratio closer to 2:1 or even 3:1.

Legume hays are naturally high in calcium, often testing at 1.0% to 2.0% calcium on a dry matter basis. Grass hays typically run lower, around 0.3% to 0.5% calcium. Phosphorus levels are generally similar across hay types, usually 0.15% to 0.30% on a dry matter basis.

If your hay analysis shows an inverted Ca:P ratio where phosphorus exceeds calcium, you need to supplement calcium to correct the imbalance. This is more common with grain-heavy diets than with forage-based feeding, but it is worth checking on your report.

Some labs also report trace minerals like copper, zinc, manganese, and selenium. These values are useful if you are working with an equine nutritionist to balance a complete ration, but for most horse owners, the major minerals calcium and phosphorus are the ones to focus on initially.

Quick Reference: Ideal Values for Horses

Here is a quick reference guide for interpreting your hay analysis results. These values are on a dry matter basis, which is the column you should use for all comparisons.

For crude protein, mature idle horses do well with 8% to 12% CP. Growing horses and broodmares need 12% to 16% CP. If your hay tests above 14% CP for a maintenance horse, you are likely overfeeding protein, which is not dangerous but wasteful.

For ADF, aim for values below 35% for the best digestibility. Moderate quality hay runs 35% to 40% ADF. Anything above 40% ADF is overmature and best used as a filler forage for easy keepers.

For NDF, values below 40% indicate highly palatable hay that horses eat eagerly. The 40% to 50% range represents good quality forage with normal intake. Values above 60% NDF reduce voluntary intake significantly.

For NSC, metabolic horses and laminitic horses need values below 10%. Healthy horses without metabolic concerns can safely consume hay with NSC values up to 20% or even higher.

For DE, typical grass hay provides 1.8 to 2.2 Mcal/kg. Legume hay delivers 2.0 to 2.4 Mcal/kg. Use these values to calculate how much hay your horse needs to meet daily energy requirements.

For moisture content, ideal horse hay runs 10% to 15%. Above 18% moisture, watch for mold and spoilage. Below 10%, the hay may be dusty and less palatable.

Grass Hay vs Legume Hay: What the Numbers Show

Hay type significantly affects your analysis results. Grass hays like timothy, orchardgrass, and bermudagrass typically test lower in protein and energy but higher in fiber than legume hays. Grass hay crude protein usually runs 6% to 12% on a dry matter basis, with ADF values between 32% and 42% depending on maturity.

Legume hays like alfalfa and clover test higher in protein, calcium, and digestible energy. Alfalfa commonly tests at 15% to 22% CP with calcium levels reaching 1.5% to 2.0%. The higher calorie density of legume hay means you feed fewer pounds to meet the same energy targets, which is why alfalfa is popular for performance horses and hard keepers.

For metabolic horses, grass hay is generally the safer default because it tends to have lower NSC values than legume hay. However, this is not always the case. I have seen grass hay tests come back with NSC values above 20% because the grass was stressed by drought or cut at the wrong time of day. That is exactly why visual inspection and hay type alone are not reliable indicators of sugar content.

Mixed grass-legume hay falls somewhere in between, which is why testing mixed hay is particularly valuable. You cannot accurately estimate the nutrient content of mixed hay from appearance alone.

When Should You Get a Hay Analysis Done?

Not every horse owner needs to test every load of hay. But for certain situations, a hay analysis moves from helpful to essential. Here is my decision framework for when testing is worth the investment.

You should absolutely get a hay analysis if your horse has Equine Metabolic Syndrome, insulin resistance, PPID (Cushing’s disease), or a history of laminitis. These conditions require careful sugar and starch management, and you simply cannot manage what you have not measured. NSC values can vary dramatically between cuttings, fields, and even bales from the same field, so guessing is risky for metabolically compromised horses.

You should strongly consider testing if your horse is an easy keeper that gains weight on air, a performance horse with high energy demands, a broodmare in late gestation or lactation, or a growing horse under two years old. In each of these cases, knowing your hay’s nutrient profile helps you fine-tune the total diet to meet specific requirements.

Testing is also worth it if you buy large quantities of hay at once. If you purchase a six-month supply from a single source, spending $20 to $30 on a hay analysis represents a tiny fraction of your total hay investment. That one-time test covers the entire load and gives you confidence in your feeding program for months.

When You Probably Do Not Need to Test

For a healthy, mature horse at maintenance level with no metabolic issues, hay testing is helpful but not essential. If your horse maintains good body condition on a forage-based diet with a ration balancer, and you are not dealing with any health concerns, you can reasonably skip testing without major consequences.

Testing is also less critical if you buy small quantities of hay frequently from changing sources. By the time you collect samples, send them to a lab, and get results back, you may have already moved on to a different load. In that situation, a hay analysis tells you about hay you no longer have.

That said, even for routine situations, a one-time baseline test of your common hay source can be educational. Seeing the actual numbers once helps you make better general feeding decisions going forward, even without testing every load.

How to Collect a Proper Hay Sample

The accuracy of your hay analysis depends entirely on the quality of your sample. If you grab a handful from one bale and send it in, your results will not represent the overall load. Here is the proper method that forage testing labs recommend.

Step 1: Obtain a hay corer, also called a hay probe. This is a hollow metal tube with a cutting tip that drills into the bale and extracts a core sample. You cannot get a representative sample by pulling flakes apart by hand. Hay corers attach to a standard electric drill and cost around $50 to $100, which is a one-time investment if you test regularly. Many county extension offices loan hay corers to horse owners for free.

Step 2: Identify which bales represent your load. To get a representative sample, you should core at least 20 bales from the same cutting, field, and lot. If you have fewer than 20 bales total, core every bale. The goal is to capture the natural variation that exists across the load.

Step 3: Core each bale from the end, drilling straight in toward the center. The round end of small square bales is the preferred sampling point because it gives you a cross-section of all the flakes. Insert the corer fully so you get a complete core from outer edge to middle of the bale.

Step 4: Combine all core samples into a single sealed plastic bag. Mix the samples gently so the composite represents the average nutrient content of the entire load. Label the bag with the date, hay type, field or supplier name, and cutting number.

Step 5: Mail or deliver the sample to a forage testing laboratory. Many state extension offices offer hay testing services, and there are also private labs like Equi-Analytical, Dairy One, and Cumberland Valley Analytical Services that specialize in forage analysis. Results typically arrive within 5 to 10 business days.

One important note: each cutting and each field should be sampled and tested separately. Nutrient content can vary significantly between cuttings from the same field due to differences in plant maturity, weather conditions, and fertilizer applications. Do not assume that second cutting from the same field will match first cutting results.

Reading Your Hay Analysis Report: A Step-by-Step Approach

When your results arrive, do not panic at the wall of numbers. Here is the order I recommend working through the report.

First, check moisture content in the As Sampled column. Confirm it falls in the safe range of 10% to 15%. If moisture is above 18%, inspect your hay for mold and consider how long you can safely store it.

Next, switch to the Dry Matter column for all remaining analysis. This is the column you will use for all comparisons and ration calculations.

Then scan crude protein to confirm it falls in an appropriate range for your horse type. Compare the value to your horse’s requirements based on age, workload, and reproductive status.

Move on to ADF and NDF to assess overall forage quality and digestibility. These two numbers tell you whether the hay was harvested at the right maturity stage and how much your horse will voluntarily consume.

Check NSC, or better yet ESC plus starch, if your horse has any metabolic concerns. This is the make-or-break number for laminitic horses and EMS cases. If NSC is above your target threshold, you may need to soak the hay to reduce sugar content before feeding, or find an alternative source.

Finally, review DE to understand the caloric density and minerals to check the calcium-to-phosphorus ratio. If anything looks off, consult an equine nutritionist who can help you balance the ration with appropriate supplements or concentrates.

Forum discussions consistently reveal that horse owners struggle most with the interpretation phase. Many report receiving results and not knowing what constitutes a good versus bad number. The pain point is real, and it is exactly why having a framework for reading the report matters. Once you know the order to check things and the target ranges to compare against, the report goes from overwhelming to manageable.

Frequently Asked Questions

Conclusion: Making Sense of Your Hay Analysis

Getting a hay analysis done is one of the most practical steps you can take toward better horse nutrition, and understanding what the numbers tell you turns raw data into actionable feeding decisions. The process costs about $20, takes minimal effort once you have a hay corer, and removes the guesswork from ration balancing.

If your horse has any metabolic concerns, testing is not optional but essential. For healthy maintenance horses, testing provides a valuable baseline that helps you make informed feeding choices. Once you learn to read the dry matter column and understand what CP, ADF, NDF, NSC, and DE each tell you, every future hay analysis becomes easier to interpret.

I recommend working with an equine nutritionist for your first analysis if the numbers feel overwhelming. A professional can walk you through your specific results and help you build a ration that meets your horse’s individual needs based on real data rather than estimates. Should you get a hay analysis done? If you care about feeding your horse correctly, the answer is yes.