Sheep Feed Testing: How to Sample and Interpret Results

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-14

Key Takeaways

Representative sampling is paramount: Collect cores from at least 10-20 bales per lot using a hay probe, or clip standing forage at grazing height (approx. 2 inches) in a zigzag pattern across the field to ensure accurate nutrient analysis.
Key analytical parameters are critical: Focus on Dry Matter (DM), Crude Protein (CP), Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF), Total Digestible Nutrients (TDN), and essential minerals like Calcium (Ca) and Phosphorus (P) to assess energy, protein, digestibility, and intake potential.
Match feed quality to specific flock needs: Interpret results against the varying requirements of production groups (e.g., lactating ewes need 13-15% CP and >65% TDN, while dry ewes require less) to prevent undernourishment and overfeeding.
Proactive management prevents deficiencies and excesses: Use test results to identify gaps in energy, protein, or mineral content and supplement precisely, avoiding costly overfeeding or detrimental mineral imbalances like high Ca:P ratios contributing to urinary calculi.
Regular testing and recordkeeping optimize flock health and efficiency: Sample new feed lots, retest stored forages periodically (e.g., every 6 months for outdoor storage), and maintain records to evaluate management practices and make informed feeding decisions.

Every sheep operation depends on feed quality, yet most producers feed their flock without knowing exactly what is in the hay, silage, or grain they are providing. Feed testing removes the guesswork. It tells you the protein, energy, fiber, and mineral content of what you are feeding, so you can match rations to the needs of your ewes, rams, lambs, and replacement stock. This article explains how to collect a representative sample, how to read a feed test report, and how to use those numbers to adjust your feeding program. It is written for sheep producers of all scales, from small flock owners to commercial operations, who want to improve flock health and reduce feed waste.

At a Glance

Test every new load or cutting of hay, and test each different forage source before feeding it to your flock.
Use a hay probe to sample bales. Collect cores from at least 10 to 20 bales per lot and combine them into one composite sample.
Sample hay about 3 to 4 weeks after harvest, once the hay has gone through the sweat phase and moisture has stabilized.
For pasture or standing forage, walk a zigzag pattern across the field and clip samples at grazing height, about 2 inches above the soil.
For silage or baleage, sample from the face of the pile or from freshly opened bales. Never sample spoiled material.
Send samples to a certified forage testing laboratory. Most labs provide sampling instructions and supplies.
Key numbers to look for on a report: dry matter, crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), calcium, phosphorus, and relative feed value (RFV) or relative forage quality (RFQ).
Interpret results against the needs of your sheep. A lactating ewe needs far more protein and energy than a dry ewe in early gestation.
Test your feed, then balance your rations. Do not guess. Guessing leads to overfeeding, underfeeding, or mineral imbalances.
Keep records of every test result. Compare results across years to evaluate your haymaking practices and pasture management.

Why Feed Testing Matters for Sheep

Sheep are ruminants with specific nutritional requirements that change across the production cycle. A ewe in late gestation carrying twins has different needs than a dry ewe in early pregnancy. A growing lamb needs more protein than a mature ram. If you feed the same ration to the entire flock without knowing its nutrient content, some animals will be undernourished and others overfed.

Underfeeding causes visible and invisible losses. Ewes that lack energy and protein produce less milk, wean lighter lambs, and have weaker colostrum. They may also experience pregnancy toxemia in late gestation. Lambs that do not get enough protein grow slowly and convert feed poorly. Rams on a low-quality diet produce fewer and less viable sperm.

Overfeeding wastes money. Protein and energy are the most expensive components of a sheep ration. Feeding a high-protein supplement when your hay already provides adequate protein is a direct loss to your bottom line. Overconditioned ewes also have more lambing difficulties and are more prone to metabolic problems.

Mineral imbalances are another hidden cost. High levels of some minerals can interfere with the absorption of others. For example, excess potassium or sulfur can reduce magnesium absorption, which can contribute to grass tetany. Too much calcium relative to phosphorus can contribute to urinary calculi in wethers and rams. A feed test tells you what is actually in your forage so you can supplement precisely.

Feed testing also helps you evaluate your haymaking and pasture management. If your hay consistently tests low in protein, you may be cutting too late, losing leaves during raking, or having rain damage. If your pasture tests low in energy, you may need to adjust your grazing rotation or renovate the stand. Feed testing turns forage quality from a mystery into a manageable variable.

Understanding Forage Quality for Sheep

Forage quality is a measure of how well a feed meets the nutritional needs of the animal eating it. For sheep, the key components are energy, protein, fiber, and minerals. Each of these affects how much forage a sheep can eat and how well it can digest that forage.

Energy is the most limiting nutrient for most sheep operations. It comes primarily from carbohydrates and fats in the forage. Energy is measured in several ways on a feed test report, including total digestible nutrients (TDN), digestible energy (DE), metabolizable energy (ME), and net energy (NE). TDN is the most common measure on forage test reports and is expressed as a percentage of dry matter.

Protein is the second most critical nutrient. Crude protein (CP) is the standard measure. It is calculated from the nitrogen content of the feed and includes both true protein and non-protein nitrogen. For sheep, the protein requirement ranges from about 8 percent for dry ewes to 15 percent or more for lactating ewes and rapidly growing lambs.

Fiber is the structural part of plants that gives them their bulk. It is measured as acid detergent fiber (ADF) and neutral detergent fiber (NDF). ADF is the cellulose and lignin portion of the plant and is inversely related to digestibility. As ADF increases, digestibility decreases. NDF includes ADF plus hemicellulose and represents the total cell wall content. NDF is related to how much forage an animal can consume. As NDF increases, intake decreases because the rumen fills up before the animal meets its energy needs.

Relative feed value (RFV) and relative forage quality (RFQ) are index numbers that combine digestibility and intake potential into a single score. RFV is calculated from ADF and NDF. RFQ is a newer index that also accounts for fiber digestibility. Higher numbers indicate better quality. For sheep, an RFV above 100 is generally adequate for dry ewes. Lactating ewes and growing lambs need RFV values of 120 or higher.

Minerals are the final piece of the puzzle. The most important to track are calcium, phosphorus, magnesium, potassium, and sulfur. Trace minerals like copper, zinc, and selenium are also important, though they are not always included in standard forage tests. You can request a mineral panel if you have specific concerns.

Step-by-Step Guide to Sampling Hay for Sheep Feed Testing

Sampling is the most important step in feed testing. A test result is only as good as the sample you submit. A poorly collected sample gives you numbers that look precise but are actually misleading. Follow these steps to collect a representative sample from hay.

Step 1: Identify Lots

A lot is a group of bales that came from the same field, were cut at the same time, and were harvested under the same conditions. If you have 200 bales of first-cutting alfalfa from one field and 150 bales of second-cutting grass hay from another field, those are two separate lots. Sample each lot separately.

Do not mix lots in one sample. If you mix first and second cutting hay, the test result will be an average that matches neither lot. You will not know whether to supplement the first cutting or the second cutting.

Step 2: Gather the Right Equipment

You need a hay probe, a clean bucket, and a sealable plastic bag. A hay probe is a hollow metal tube that you drill into the end of a bale to pull out a core sample. Probes are available from forage testing labs, agricultural supply stores, and online retailers. A probe with a 3/8-inch or 1/2-inch diameter core works well for most hay types.

If you do not have a hay probe, you can use a drill with a hole saw attachment, though this is less effective. Hand-pulling samples from the center of bales is not recommended because it is difficult to get a consistent core and you risk injury from the hay.

Step 3: Decide How Many Bales to Sample

Sample at least 10 to 20 bales from each lot. The more bales you sample, the more accurate your composite sample will be. For large lots, sample 20 bales. For small lots, sample at least 10. If the lot contains fewer than 10 bales, sample all of them.

Step 4: Choose Bales at Random

Do not sample only the bales that look good or only the bales that look poor. You want a representative sample of the entire lot. Walk through the stack or field and select bales at random. If the bales are stacked, sample from different levels and locations. Do not always sample from the same side of the stack.

Step 5: Take Cores

Insert the probe into the end of each bale, not the side. The end of a bale is more representative of the entire bale because it samples across all the flakes. Push the probe in as far as it will go, then withdraw it and push the core out of the probe into the bucket.

For small square bales, take one core from each bale. For large round bales, take two cores from each bale, one from the center and one from the edge. For large square bales, take one core from each bale and sample more bales.

Step 6: Combine the Cores

Combine all the cores from the same lot into one bucket. Mix them thoroughly by hand. Remove any foreign material like leaves, stems, or dirt that fell into the bucket. The goal is a uniform composite sample.

Step 7: Fill the Sample Bag

Fill the sample bag with about 1 to 2 cups of the mixed material. Do not pack the bag tightly. The lab needs enough material to run all the tests, but they do not need the entire bucket. Squeeze the air out of the bag and seal it.

Step 8: Label and Ship

Label the bag with your name, the lot identification, the forage type, and the date. Most labs provide a submission form. Fill it out completely and include it with the sample. Ship the sample promptly. Do not let it sit in a hot truck or a damp barn. Moisture can cause the sample to mold and give inaccurate results.

Step 9: Store a Backup Sample

Keep a small backup sample from each lot in a labeled paper bag. Store it in a dry, cool place. If you have a question about the test results or need to retest, you have a reference sample to compare.

How to Sample Baleage and Silage for Sheep

Baleage and silage require different sampling techniques because the forage is fermented and higher in moisture. The fermentation process changes the nutrient content, and the distribution of nutrients within the silage mass can be uneven.

For baleage, sample each bale individually if you are feeding bales one at a time. Use a hay probe to take cores from the end of the bale. Take at least 5 cores from different locations on the end face. Combine the cores into one composite sample for that bale.

If you are feeding multiple bales from the same cutting and harvest date, you can treat them as a lot and sample across bales. Take cores from 5 to 10 bales and combine them. Be aware that baleage can vary more than dry hay because fermentation is not uniform.

For silage from a bunker or pile, sample from the face of the silage. Remove the loose, spoiled material from the face first. Then take samples from the freshly exposed face, from top to bottom and side to side. Collect about 1 to 2 cups of material and place it in a sealable bag. Do not sample only from one spot on the face.

For silage from an upright silo, sample as you remove feed from the silo. Take small handfuls from different locations in the load and combine them. Collect samples over several days if you want a more accurate picture of the silage you are feeding.

For all silage samples, ship them to the lab immediately. The high moisture content means the sample can spoil quickly. Many labs offer wet chemistry analysis for silage, which is more accurate than near-infrared reflectance (NIR) analysis for fermented feeds.

How to Sample Pasture and Standing Forage for Sheep

Sampling pasture is more complex than sampling hay because the forage is living and changing. The nutrient content of pasture varies with plant species, maturity, soil fertility, and weather. Forage quality declines as plants mature and produce seed heads.

If you want to know what your sheep are actually eating, sample the forage at the height that sheep are grazing. Sheep are selective grazers and prefer leaves over stems. A sample that includes all plant material at ground level will test lower in quality than what the sheep actually consume.

To sample pasture, follow these steps:

Walk a zigzag pattern across the field. Stop at 10 to 15 locations that represent the range of plant growth and species in the field. At each stop, clip the forage at grazing height, about 2 inches above the soil. Collect about a handful of material from each location and combine it in a bucket.

If you want to estimate what sheep are selecting rather than what is growing, you can use a technique called hand-plucking. Walk the field and mimic the grazing behavior of the sheep. Pluck the leaves and tender stems that sheep would eat, avoiding the coarse stems and dead material. This gives you a sample of the diet the sheep are actually consuming.

Mix the clipped or plucked samples thoroughly and fill a sample bag with about 1 to 2 cups of material. Label and ship as described above.

For pasture sampling, the timing matters. Sample at the stage of growth that you want to evaluate. If you are planning to graze a field next week, sample it now. If you are trying to decide whether to supplement, sample the pasture at the current growth stage and compare it to the requirements of your sheep.

Keep in mind that pasture quality changes quickly. A test result from a pasture sampled in May will not be accurate in July. Sample pasture at least monthly during the grazing season if you are relying on it as a primary feed source.

How to Sample Grains and Concentrates for Sheep

Grains and commercial concentrates are more uniform than forage, but they still deserve occasional testing. If you buy grain from a local elevator or feed mill, the supplier may provide a guaranteed analysis. This is useful, but it does not tell you the actual nutrient content of the specific batch you purchased.

To sample grain, take small handfuls from multiple bags or from different parts of a bin. Combine them in a bucket and mix well. Fill a sample bag with about 1 cup of material. For pellets or cubes, take samples from multiple bags or from different depths in the bin.

If you mix your own rations, test each ingredient separately. Do not test the final mix unless you want to verify that you mixed it correctly. Testing each ingredient tells you what you are actually putting into the mix.

Grain samples are less perishable than forage samples, but they should still be shipped promptly. Moisture content is an important measure for grain because it affects storage life and nutrient density.

Choosing a Feed Testing Laboratory

Several commercial laboratories analyze feed samples for livestock producers. Your local cooperative extension office can recommend a lab that serves your region. Many state universities operate forage testing labs that accept samples from the public.

When choosing a lab, consider the following:

Turnaround time. Most labs return results within 5 to 10 business days after receiving the sample. If you need results sooner, ask about rush service.

Tests offered. Standard forage tests typically include dry matter, crude protein, ADF, NDF, TDN, and sometimes minerals. Some labs offer packages that include RFV or RFQ. Ask what is included in the standard package.

Cost. Standard forage tests cost between $15 and $30 per sample. Mineral panels add $10 to $20. This is a small investment compared to the cost of overfeeding or underfeeding your flock.

Analytical method. Labs use either wet chemistry or near-infrared reflectance (NIR) analysis. Wet chemistry is more accurate but takes longer. NIR is faster and less expensive but is calibrated against wet chemistry results. Both methods are acceptable for routine feed testing.

Sampling supplies. Most labs provide free sampling bags, submission forms, and instructions. Some provide hay probes for purchase or loan.

Reading a Feed Test Report

A feed test report can look intimidating with its columns of numbers and abbreviations. Once you understand what each number means, the report becomes a useful management tool. Here is a walkthrough of a typical forage test report.

Dry Matter and Moisture

Dry matter (DM) is the percentage of the feed that is not water. It is the foundation for all other measurements. Forage test results are reported on a dry matter basis, meaning the nutrient percentages are calculated as if the feed had no moisture.

Moisture is simply 100 minus dry matter. Hay typically has 88 to 92 percent dry matter. Baleage has 40 to 60 percent dry matter. Silage has 30 to 40 percent dry matter. Pasture has 15 to 25 percent dry matter.

The dry matter percentage tells you how much feed you are actually delivering. If you feed 10 pounds of hay that is 90 percent dry matter, you are providing 9 pounds of dry matter. If you feed 10 pounds of baleage that is 50 percent dry matter, you are providing only 5 pounds of dry matter.

Crude Protein

Crude protein (CP) is reported as a percentage of dry matter. It is calculated by measuring the nitrogen content of the feed and multiplying by 6.25. This assumes that protein is 16 percent nitrogen.

For sheep, the crude protein requirement varies by production stage:

Dry ewes in early gestation: 8 to 9 percent
Ewes in mid gestation: 9 to 10 percent
Ewes in late gestation: 11 to 12 percent
Lactating ewes: 13 to 15 percent
Growing lambs: 14 to 16 percent
Rams in breeding season: 10 to 12 percent

If your hay tests at 8 percent crude protein and you are feeding lactating ewes, you need to supplement with a higher protein feed. If your hay tests at 12 percent and you are feeding dry ewes, you are overfeeding protein.

Acid Detergent Fiber

Acid detergent fiber (ADF) is reported as a percentage of dry matter. It represents the cellulose and lignin portion of the plant. ADF is inversely related to digestibility. As ADF increases, the energy value of the forage decreases.

For sheep, ADF values below 30 percent are considered excellent. Values of 30 to 35 percent are good. Values of 35 to 40 percent are fair. Values above 40 percent are poor and indicate low digestibility.

ADF is used to calculate TDN and net energy values. Forages with lower ADF have higher energy values.

Neutral Detergent Fiber

Neutral detergent fiber (NDF) is reported as a percentage of dry matter. It represents the total cell wall content of the plant, including cellulose, hemicellulose, and lignin. NDF is related to intake potential. As NDF increases, the forage becomes more bulky and animals cannot consume enough to meet their energy needs.

For sheep, NDF values below 40 percent are excellent. Values of 40 to 50 percent are good. Values of 50 to 60 percent are fair. Values above 60 percent are poor.

Total Digestible Nutrients

Total digestible nutrients (TDN) is reported as a percentage of dry matter. It is an estimate of the energy value of the feed. TDN is calculated from ADF using a formula. For sheep, TDN values of 55 to 60 percent are adequate for dry ewes. Lactating ewes and growing lambs need TDN values of 65 to 70 percent.

Some labs report digestible energy (DE), metabolizable energy (ME), or net energy (NE) instead of TDN. These are related measures. For sheep, the relationship is approximately:

1 pound TDN equals about 2 megacalories of digestible energy. Metabolizable energy is about 82 percent of digestible energy. Net energy varies by the production function.

Relative Feed Value and Relative Forage Quality

Relative feed value (RFV) is an index that combines ADF and NDF into a single score. It is calculated as:

RFV = (88.9 - (0.779 x ADF)) x (120 / NDF)

RFV is most useful for comparing legume hays like alfalfa. For sheep, RFV above 100 is adequate for dry ewes. Values above 120 are needed for lactating ewes and growing lambs.

Relative forage quality (RFQ) is a newer index that also accounts for fiber digestibility. It is a better measure for grass hays and warm-season forages. RFQ values are typically higher than RFV values for the same forage.

Minerals

Mineral concentrations are reported as a percentage of dry matter for macrominerals and as parts per million (ppm) for trace minerals. The most important minerals to check are:

Calcium (Ca): Sheep need 0.3 to 0.8 percent calcium in the diet, depending on production stage. Lactating ewes need more.

Phosphorus (P): Sheep need 0.2 to 0.4 percent phosphorus. The calcium to phosphorus ratio should be between 1.5 to 1 and 2 to 1 for most sheep. Wethers and rams fed high calcium with low phosphorus are at risk for urinary calculi.

Magnesium (Mg): Sheep need 0.12 to 0.18 percent magnesium. Low magnesium in lush spring pasture can cause grass tetany.

Potassium (K): Sheep need 0.5 to 0.8 percent potassium. High potassium levels can interfere with magnesium absorption.

Sulfur (S): Sheep need 0.15 to 0.25 percent sulfur. High sulfur can interfere with copper absorption and cause policencephalomalacia.

For trace minerals, the most important are copper, zinc, manganese, and selenium. Copper is especially important for sheep because they are highly sensitive to copper toxicity. The maximum tolerable level of copper for sheep is about 15 to 25 ppm in the total diet. Sheep feeds should never contain added copper.

Interpreting Feed Test Results for Your Flock

Once you have the test results, you need to interpret them in the context of your flock. The same hay can be excellent for dry ewes and inadequate for lactating ewes. The question is not whether the feed is good, but whether it meets the needs of the animals you are feeding.

Match Feed Quality to Animal Needs

Divide your flock into production groups based on nutritional needs. At minimum, separate dry ewes, ewes in late gestation, lactating ewes, and growing lambs. Rams may need their own group during and after the breeding season.

Feed the highest quality forage to the animals with the highest requirements. Lactating ewes and growing lambs get the best hay. Dry ewes and rams can be fed lower quality forage. This is called targeted feeding and it saves money by matching feed quality to animal needs.

Calculate How Much to Feed

The test report tells you the nutrient concentration of the feed. To determine how much to feed, you need to know the nutrient requirements of your sheep and the amount of feed they will consume.

A mature ewe will consume about 2 to 4 percent of her body weight in dry matter per day. A 150-pound ewe will eat about 3 to 6 pounds of dry matter per day. The exact amount depends on the quality of the forage and the production stage of the ewe.

To calculate whether the forage meets the ewe's needs, multiply the dry matter intake by the nutrient concentration. For example, if a ewe eats 4 pounds of dry matter per day and the hay is 10 percent crude protein, she receives 0.4 pounds of protein per day. Compare this to her protein requirement.

Identify Deficiencies and Excesses

The most common deficiencies in sheep rations are energy and protein. Minerals can also be deficient or imbalanced. Compare the nutrient content of your forage to the requirements of your sheep and identify the gaps.

If the forage is low in protein, add a protein supplement like soybean meal, cottonseed meal, or a commercial supplement. If the forage is low in energy, add a grain supplement like corn or barley. If the forage is low in calcium, add limestone. If it is low in phosphorus, add dicalcium phosphate.

Be careful not to overcorrect. Adding too much of one mineral can cause problems with another. Work with a nutritionist or extension agent to balance the ration.

Adjust for Feed Refusals and Waste

Sheep waste feed. They trample hay, sort out leaves, and refuse stems. The actual amount of nutrients consumed is lower than the amount offered. Adjust your feeding rates to account for waste.

Hay fed in bale feeders has less waste than hay fed on the ground. Feeding hay in small amounts that sheep can clean up in a few hours reduces waste. Do not feed so much that sheep can pick through it and waste the leaves.

Common Mistakes in Feed Sampling and Testing

Sampling Too Few Bales

A sample from 3 bales does not represent a lot of 200 bales. The nutrient content of hay varies from bale to bale based on soil fertility, plant maturity, and curing conditions. Sample at least 10 to 20 bales per lot to get a representative sample.

Sampling Only the Best or Worst Bales

If you sample only the bales that look good, you will overestimate the quality of the lot. If you sample only the bales that look poor, you will underestimate it. Choose bales at random to get an accurate picture.

Sampling Hay Too Soon After Harvest

Freshly baled hay goes through a sweat phase as excess moisture dissipates. The nutrient content changes during this period. Wait 3 to 4 weeks after harvest before sampling. This allows the hay to stabilize.

Mixing Different Lots

Do not combine first cutting and second cutting hay in one sample. Do not combine hay from different fields. Each lot must be sampled separately. The test result is an average of the material in the sample. If you mix lots, the result matches neither.

Sampling Spoiled Feed

Do not sample moldy, rotten, or weather-damaged feed. The test result will not represent the feed you are feeding. If you have spoiled bales in a lot, remove them and feed them separately or discard them.

Shipping Samples Too Late

Feed samples are perishable. Moisture in the sample can cause mold growth and nutrient breakdown. Ship samples the same day you collect them. If you cannot ship immediately, store the sample in a refrigerator.

Not Labeling Samples

An unlabeled sample is useless. The lab cannot tell you which lot it came from. Label every sample with your name, the lot identification, the forage type, and the date.

Ignoring the Results

Collecting a sample and sending it to the lab is only the first step. The test result is worthless if you do not use it. Compare the results to your flock's requirements and adjust your feeding program accordingly.

Using Feed Test Results to Balance Sheep Rations

Balancing a ration means providing the right amount of each nutrient to meet the needs of the animal. For most sheep operations, the goal is to meet energy and protein requirements while providing adequate minerals and vitamins.

Step 1: Determine Nutrient Requirements

The National Research Council (NRC) publishes nutrient requirements for sheep. Your local extension office can provide tables that list requirements by production stage. The key numbers are dry matter intake, crude protein, TDN, calcium, and phosphorus.

Step 2: Determine What the Forage Provides

Using the feed test results, calculate how much of each nutrient the forage provides. Multiply the dry matter intake by the nutrient concentration. This gives you the nutrient intake from forage.

Step 3: Identify the Gaps

Subtract the nutrients provided by the forage from the nutrient requirements. The difference is the gap that must be filled with supplements.

Step 4: Choose Supplements

Select supplements that fill the gaps without creating excesses. If the forage is low in protein but adequate in energy, use a high protein supplement. If it is low in energy but adequate in protein, use a grain supplement. If both are low, use a combination.

Step 5: Calculate Supplement Amounts

Calculate how much supplement to feed to fill the gaps. For example, if the ewes need 0.1 pounds more protein per day and soybean meal is 50 percent protein, feed 0.2 pounds of soybean meal per ewe per day.

Step 6: Monitor and Adjust

Feed the balanced ration for a week or two, then observe the condition of your sheep. Are they maintaining body condition? Is milk production adequate? Adjust the ration as needed based on animal performance.

Monitoring Body Condition Alongside Feed Tests

Feed tests tell you what is in the feed. Body condition scoring tells you how well the sheep are using that feed. Together, they give you a complete picture of your flock's nutritional status.

Body condition scoring (BCS) is a system for evaluating the fat and muscle cover on a sheep. Sheep are scored on a scale of 1 to 5, with 1 being emaciated and 5 being obese. The ideal score depends on the production stage:

Dry ewes: 2.5 to 3.0
Ewes at breeding: 3.0 to 3.5
Ewes in early gestation: 3.0 to 3.5
Ewes in late gestation: 3.0 to 3.5
Lactating ewes: 2.5 to 3.0
Rams: 3.0 to 3.5

Score your ewes at key production points: at weaning, at breeding, at mid gestation, and at lambing. If ewes are losing condition despite adequate feed, the ration may be inadequate or the feed test may not represent what the sheep are actually eating.

To score body condition, feel the spine and the loin area. Run your hand over the backbone. You should be able to feel the vertebrae but they should not be sharp. Then feel the loin, the area between the last rib and the hip bone. There should be a moderate fat cover.

Body condition scoring is a skill that improves with practice. Ask your veterinarian or extension agent to demonstrate the technique. Practice on sheep of known condition to calibrate your fingers.

Recordkeeping for Feed Testing

Feed testing is most valuable when you track results over time. A simple recordkeeping system helps you compare forage quality across years, evaluate your haymaking practices, and make better purchasing decisions.

For each feed test, record:

Date of sampling
Field or source identification
Forage type and cutting
Harvest date
Baling or storage method
Test results for DM, CP, ADF, NDF, TDN, RFV, and minerals
Cost per ton
Any notes about weather, fertility, or harvest conditions

Store your records in a notebook or a spreadsheet. Many producers keep a three-ring binder with a page for each lot of hay. At the end of the year, review your records to see which fields produced the best forage and which harvest practices worked best.

Feed test records are also useful when buying feed. If you are considering purchasing hay from a new supplier, ask for test results from previous lots. Compare them to your own records to determine whether the hay will meet your flock's needs.

When to Retest Feed

Feed quality changes over time, especially for stored forages. Hay stored outdoors loses quality faster than hay stored under cover. The outer layer of round bales stored outside can lose 20 to 30 percent of its dry matter and nutrient content.

Retest your feed in these situations:

When you open a new lot of hay that you have not tested
When you notice a visible change in hay color, smell, or leafiness
When sheep performance declines despite feeding the same ration
When you suspect mold or heating in stored hay
When you change the source of any feed ingredient

For long-term storage, retest hay every 6 months if it is stored outdoors. Hay stored indoors can be tested once at harvest and again before feeding if storage exceeds 6 months.

Common Feed Quality Problems in Sheep Operations

Low Protein in Grass Hay

Grass hay cut late in the season often tests below 8 percent crude protein. This is inadequate for most sheep, especially lactating ewes and growing lambs. The solution is to supplement with a high protein feed or to feed a legume hay.

High Fiber and Low Energy in Mature Forage

Forage that is cut after seed head emergence has high ADF and NDF and low TDN. Sheep will eat less of it and digest it poorly. The solution is to cut hay earlier in the season or to supplement with grain.

Mold and Dust in Hay

Moldy hay is unpalatable and can cause respiratory problems and digestive upsets in sheep. It also has reduced nutrient content. Do not feed moldy hay to sheep. If you must feed it, mix it with good quality hay and monitor the sheep closely.

High Potassium in Lush Pasture

Lush spring pasture can be high in potassium and low in magnesium. This combination can cause grass tetany in lactating ewes. The solution is to provide a magnesium supplement and to avoid turning hungry ewes onto lush pasture.

High Copper in Commercial Feeds

Sheep are sensitive to copper. Some cattle and swine feeds contain added copper at levels that are toxic to sheep. Never feed sheep feeds formulated for other species. Check the label of any commercial feed before feeding it to sheep.

Troubleshooting Feed Test Results That Look Wrong

Sometimes a feed test result does not match your expectations. Before you adjust your feeding program, consider whether the sample was representative and whether the lab analysis was accurate.

If the crude protein is much higher or lower than expected, the sample may have been contaminated. Leaves are higher in protein than stems. If your sample had more leaves than the bales, the protein will be overestimated. If it had more stems, it will be underestimated.

If the dry matter is higher than expected, the sample may have dried out before analysis. If it is lower than expected, the sample may have absorbed moisture during shipping.

If you suspect a bad test, resample the lot and submit a new sample. Many labs will rerun a sample at no charge if you suspect an error. Compare the two results. If they are very different, there may be a problem with the lot itself or with your sampling technique.

When to Call a Veterinarian or Extension Agent

Feed testing is a management tool, not a diagnostic tool. If your sheep are showing signs of illness or poor performance, a feed test alone cannot identify the cause. Call your veterinarian if you see:

Multiple sheep with weight loss despite adequate feed
Sheep with diarrhea, coughing, or nasal discharge
Ewes with pregnancy toxemia or ketosis
Lambs with poor growth rates or high death loss
Rams with reduced fertility or libido
Any sheep showing neurological signs like circling, head pressing, or seizures

These signs can indicate nutritional problems, but they can also indicate infectious disease, parasites, or toxicities. A veterinarian can help you determine the cause and develop a treatment plan.

Your local extension agent can help you interpret feed test results, balance rations, and develop a feeding program. Extension agents have access to nutritionists and can help you troubleshoot feed quality problems. They can also help you evaluate your haymaking and pasture management practices.

If you suspect a specific nutrient toxicity, such as copper poisoning or sulfur toxicity, contact your veterinarian immediately. These conditions can be fatal and require prompt treatment.

Frequently Asked Questions

How often should I test my sheep feed?

Test every new lot of hay or forage before feeding it to your sheep. If you buy hay from multiple sources, test each source. For pasture, test at least monthly during the grazing season. For stored hay, retest every 6 months if stored outdoors. Testing frequency depends on how much variation you see in your feed and how sensitive your production stage is to nutrient changes.

How much does a feed test cost?

A standard forage test costs between $15 and $30 per sample. This includes dry matter, crude protein, ADF, NDF, and TDN. Adding a mineral panel costs an additional $10 to $20. Some labs offer discounted rates for multiple samples. The cost is small compared to the expense of overfeeding protein or underfeeding energy to your flock.

Can I test hay that is already being fed?

Yes. You can sample from the bales you are currently feeding. Use a hay probe to take cores from the end of each bale before you feed it. Collect cores from 10 to 20 bales over several days and combine them into one composite sample. This gives you a picture of the hay as the sheep are actually consuming it.

What is the difference between RFV and RFQ?

Relative feed value (RFV) is calculated from ADF and NDF. It is a simple index that works well for legumes like alfalfa. Relative forage quality (RFQ) also accounts for fiber digestibility, making it more accurate for grasses and warm-season forages. RFQ values are typically higher than RFV values for the same forage. Use RFQ if your lab provides it, especially for grass hay.

My hay tested low in protein. What should I feed instead?

If your hay is below 8 percent crude protein, you need to supplement with a higher protein feed. Options include soybean meal, cottonseed meal, canola meal, or a commercial sheep supplement. Alfalfa hay is also a good protein supplement for sheep on low protein grass hay. The amount to feed depends on the protein gap and the protein content of the supplement.

Can I feed sheep cattle hay?

You can feed sheep hay that was harvested for cattle, but you need to know the nutrient content. Cattle hay is often cut later and is lower in quality than sheep hay. Test the hay and compare the results to your sheep's requirements. Also check for copper. Some cattle hay is grown on soils with high copper levels or is fertilized with products that contain copper. Sheep are sensitive to copper toxicity.

How do I know if my sheep are getting enough energy?

The best indicators are body condition and lamb growth. Score your ewes at regular intervals. If they are maintaining condition through gestation and lactation, they are getting enough energy. Weigh your lambs at birth and at weaning. Compare their growth to breed standards. If lambs are growing below expectations, the ewes may not be producing enough milk due to low energy intake.

What minerals should I supplement to sheep on hay?

Most sheep on hay need supplemental salt and a sheep-specific mineral mix. The mineral mix should contain calcium, phosphorus, and trace minerals like zinc and selenium. Do not feed cattle mineral mixes to sheep because they often contain high copper levels. Provide loose mineral rather than block form, because sheep have difficulty consuming enough from blocks.

Related Farming Guides

This section will be populated with links to other farming guides on this site. Check back soon for related articles on sheep nutrition, flock health, and pasture management.

Related Clinical & Scientific Guides

References

American Consortium for Small Ruminant Parasite Control (ACSRPC): https://www.wormx.info/
USDA APHIS Sheep Health: https://www.aphis.usda.gov/livestock-poultry-disease/sheep-goats
FAO Sheep and Goat Production: https://www.fao.org/animal-production/en/
FAO Animal Production and Health: https://www.fao.org/animal-production/en/
WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/

This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.