Dairy Cow Forage Selection: Matching Quality to Production Needs

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

Key Takeaways

• Forage quality, measured by digestibility (NDFD) and fiber content (NDF, ADF), directly impacts dry matter intake and milk production; high-producing cows require forage with NDF below 40% and NDFD above 50%.
• Harvest timing is paramount for forage quality; cutting legumes at bud to early bloom and grasses at boot to early heading stages maximizes nutrient density and digestibility, with delays significantly reducing protein and energy.
• Silage offers reduced weather risk and potentially higher leaf retention compared to hay, but requires specialized equipment and careful management to prevent spoilage from anaerobic fermentation, while hay provides storage flexibility and easier transport.
• Legumes like alfalfa offer higher crude protein (18-22%) and lower NDF than grasses, supporting greater intake and milk yield, whereas grasses excel in energy density when cut young and are suitable for dry cows due to lower protein and calcium.
• Matching forage to production stage is critical: early lactation cows need the highest quality (CP >19%, NDF <40%, NDFD >50%), while dry cows benefit from lower quality grass hay (CP 10-14%, NDF 50-60%) to prevent metabolic issues.
• Consistent ration feeding and gradual transitions (7-10 days) when switching forages are essential to prevent digestive upset and maintain rumen health, as abrupt changes disrupt microbial populations.

Forage is the foundation of every dairy ration. The quality of the hay, silage, or pasture you feed directly drives milk production, milk components, cow health, and your feed bill. Choosing the right forage for your dairy cows is not a one-time decision. It is a seasonal process that requires you to match the nutrient profile of what you grow or buy to the specific production stage of your herd. This guide explains how to evaluate forage quality, compare hay versus silage, weigh legumes against grasses, and build a feeding plan that supports milk yield without sacrificing rumen health. It is written for dairy producers, herd managers, and farm employees who want a practical framework for making better forage decisions.

At a Glance

• Match forage to production stage. High-producing cows in early lactation need the highest quality forage you have. Dry cows and late-lactation cows can use lower quality feed.
• Quality starts at harvest. Cutting at the right maturity stage does more for forage quality than any additive or mixer adjustment you make later.
• Hay versus silage is a storage and feeding system choice. Both can support excellent production when harvested correctly. Your climate, storage capacity, and labor determine which works best for you.
• Legumes beat grasses on protein and intake. Alfalfa and clover offer more protein and digestible fiber per pound than grasses. Grasses offer better energy density when cut young and are easier to manage in some soils.
• Test every cutting and every load you buy. You cannot balance a ration on guesses. A forage test costs far less than a drop in milk production or a case of ketosis.
• Feed a consistent ration. Cows hate change. When you switch forages, blend the transition over at least one full week.
• Watch the cow, not just the lab report. Manure consistency, rumen fill, body condition, and milk fat are your best indicators of whether a forage is working.

Why Forage Quality Matters More Than You Think

Dairy cows are ruminants. Their digestive system is designed to process large volumes of fibrous plant material. Forage provides the physical fiber that stimulates chewing, saliva production, and rumen contractions. This fiber keeps the rumen environment stable and prevents the acidosis problems that come from feeding too much grain. But forage is not just a filler. It is a primary source of energy, protein, and minerals.

The challenge is that forage quality varies enormously. A hay crop cut at the right stage might contain 20 percent crude protein and 30 percent neutral detergent fiber (NDF). The same field cut three weeks later might test at 12 percent protein and 45 percent NDF. That difference changes your entire ration. It changes how much grain you need to buy, how much milk your cows produce, and how healthy your herd stays through the winter.

Forage quality is best understood as a measure of digestibility. A high quality forage is one that the cow can break down efficiently in the rumen. When fiber is highly digestible, the cow gets more energy from each pound of feed. She also eats more, because digestible fiber moves through the rumen faster, leaving room for more feed. This is why high quality forage supports high dry matter intake, and high dry matter intake is the single best predictor of milk production.

The relationship between forage quality and intake is worth understanding in detail. Cows fill their rumen to a physical limit. When forage fiber is slow to digest, the rumen stays full longer, and the cow eats less. When fiber digests quickly, the rumen empties faster, and the cow takes in more total feed. A high producing cow needs to eat about 4 percent of her body weight in dry matter each day. A 1,400 pound cow needs about 56 pounds of dry matter per day. If your forage is low quality and slow to digest, she simply cannot physically eat enough to support high milk production. No amount of grain supplementation can fully overcome this limit.

Forage quality also affects milk components, especially milk fat. Milk fat synthesis depends on adequate effective fiber in the ration. Effective fiber is the physical structure that stimulates cud chewing and maintains rumen pH. If your forage is chopped too fine, or if you feed too much grain, the rumen pH drops, and milk fat percentage falls. This is why forage selection is not just about energy and protein. It is about maintaining the physical integrity of the ration.

Understanding Forage Testing and Quality Terms

Before you can choose between hay and silage, or legumes and grasses, you need to understand how forage quality is measured. Forage testing is the only reliable way to know what you are feeding. Every load of hay and every silage bunker should be tested. The lab report gives you the numbers you need to balance your ration. Here are the key terms you will see on a standard forage test.

Dry matter (DM) tells you how much water is in the feed. Fresh pasture might be 18 to 25 percent dry matter. Hay is typically 88 to 92 percent dry matter. Silage ranges from 30 to 45 percent dry matter depending on the crop and harvest method. You need dry matter to calculate how many pounds of each feed to put in the mixer. When you balance a ration, all the numbers are calculated on a dry matter basis.

Crude protein (CP) is the total nitrogen content of the forage multiplied by 6.25. It is a starting point, not the whole story. Legumes such as alfalfa typically test 18 to 22 percent crude protein when harvested at the right stage. Grasses are lower, usually 12 to 18 percent. But crude protein does not tell you how much of that protein is available to the cow. That is where the next two numbers come in.

Neutral detergent fiber (NDF) measures the total fiber content of the plant. This includes cellulose, hemicellulose, and lignin. NDF is the best predictor of dry matter intake. As NDF goes up, intake goes down. High quality alfalfa might test 35 to 40 percent NDF. Mature grass hay can test 55 to 65 percent NDF. Forage NDF is one of the most important numbers on the report because it tells you how much the cow can eat.

Acid detergent fiber (ADF) measures the cellulose and lignin portion of the fiber. ADF is inversely related to digestibility. As ADF goes up, energy goes down. ADF is used to calculate the energy value of the forage. High quality legumes have ADF values in the high 20s to low 30s. Mature grasses can have ADF values above 40.

Neutral detergent fiber digestibility (NDFD) is a newer test that measures how digestible the fiber actually is. This is a 30 or 48 hour in vitro test. NDFD is a powerful tool for comparing forages because two hays can have the same NDF but very different digestibility. A forage with high NDFD supports higher intake and more milk. Look for NDFD values above 50 percent for high producing herds.

Relative feed value (RFV) is a calculated index that combines ADF and NDF. It is used primarily for marketing hay. An RFV of 100 equals full bloom alfalfa. Values above 150 are excellent. Values below 90 are poor. RFV is useful for comparing hays, but it does not account for protein or digestibility. It is a starting point, not a complete evaluation.

Relative forage quality (RFQ) is a newer index that includes NDFD. It is a better predictor of animal performance than RFV. When you compare forages, ask your lab for RFQ in addition to RFV. A forage with a high RFQ will support more intake and more milk than one with a high RFV but low NDFD.

Minerals matter too. Calcium, phosphorus, magnesium, potassium, and sulfur all appear on the forage test. These are important for balancing the total ration, especially for dry cows. High potassium forages can contribute to milk fever in fresh cows. Always test for minerals, not just protein and fiber.

Hay Versus Silage for Dairy Cows

The choice between hay and silage is a choice between two storage and feeding systems. Both can produce excellent milk. Both can fail badly if managed poorly. Your decision should be based on your climate, your storage infrastructure, your labor supply, and your feeding setup. Here is an honest comparison.

Hay for Dairy Cows

Hay is forage that has been dried to below 15 percent moisture and stored in a dry environment. The main advantage of hay is flexibility. You can buy it from multiple sources, store it for years, and feed it without worrying about fermentation or spoilage at feedout. Hay is easier to transport than silage, and it is easier to sell if you have surplus. For small herds, hay is often the most practical choice because it does not require expensive harvest equipment or a sealed storage structure.

The main disadvantage of hay is weather risk. Getting forage dry enough to bale without rain damage is a challenge in many regions. Rain on cut forage leaches soluble sugars and protein, reducing quality dramatically. Hay that is baled too wet can mold and heat, which reduces palatability and can cause respiratory problems in cows. Hay that is baled too dry loses leaves, which are the most nutritious part of legumes.

Hay quality depends heavily on harvest timing. For legumes, cut at bud to early bloom stage. For grasses, cut at boot to early heading stage. Cutting early preserves digestibility but reduces yield. Cutting late increases yield but lowers quality. The right balance depends on your herd's production level and your ability to supplement with grain.

Hay storage matters as much as harvest. Hay stored outside on the ground loses dry matter and quality. The bottom bales rot, and the top bales weather. Store hay on a well-drained surface, off the ground, and under cover if possible. If you must store outside, use a good tarp and keep the stack tight to shed water. The difference between protected and unprotected hay can be 10 to 15 percent dry matter loss over a winter.

Silage for Dairy Cows

Silage is forage that is preserved by fermentation. The crop is chopped at 30 to 45 percent dry matter and packed tightly in a bunker, bag, or tower to exclude oxygen. Lactic acid bacteria convert sugars to acid, which drops the pH and preserves the crop. Silage has several advantages over hay.

Silage reduces weather risk. You can chop silage at a higher moisture than hay, so you do not need the same drying window. In wet climates, silage is often the only practical way to preserve high quality forage. Silage also captures more of the leaf material because there is less handling and shattering. This means silage often has higher quality than hay made from the same field.

Silage is well suited to mechanized feeding. It can be loaded with a skid steer or silage defacer, weighed accurately, and mixed in a TMR. Silage is also palatable to cows. Most cows prefer well-fermented silage to dry hay. This can support higher dry matter intake.

The disadvantages of silage are significant. You need specialized harvest equipment, storage structures, and the management skill to pack and seal the crop properly. Poorly packed silage spoils. Spoiled silage is a source of mold, mycotoxins, and clostridia, all of which can cause serious health problems. Silage also has a limited feedout window. Once you open a bunker or bag, the face must be removed fast enough to prevent heating and spoilage. A small herd may not feed enough per day to keep the face fresh.

Silage quality also depends on harvest timing, just like hay. The ideal dry matter for corn silage is 32 to 38 percent. For haylage, the ideal is 40 to 50 percent dry matter, which is wetter than corn silage. Harvesting too wet produces a butyric acid fermentation with a foul smell and poor intake. Harvesting too dry prevents proper packing and leads to heating and mold.

Making the Decision

For most dairy operations, the best approach is a combination. Corn silage provides a high energy forage that is cheap per pound of energy. Haylage provides a high protein forage that is ideal for lactating cows. Dry hay is valuable for dry cows, heifers, and as a source of long fiber in the TMR. Many top herds feed all three.

If you are starting from scratch, think about your labor and equipment first. Silage requires a chopper, wagons, a pack tractor, and a loader. Hay requires a mower, rake, baler, and hay handling equipment. If you already have hay equipment, start with high quality hay. If you have the infrastructure for silage, it is often the more consistent route to high quality forage.

Here is a practical decision framework. If your annual rainfall is above 25 inches and you struggle to get hay dry, prioritize silage. If you have a small herd and limited storage, prioritize hay. If you have a large herd and a TMR mixer, silage is usually the backbone of the ration. If you buy forage rather than grow it, hay is easier to buy in small quantities and easier to evaluate visually.

Legume Versus Grass Forage

The legume versus grass debate is really a debate about protein, fiber digestibility, and agronomic fit. Both plant families can produce excellent dairy forage. The right choice depends on your soil, your climate, your crop rotation, and the needs of your herd.

Legumes for Dairy Cows

Legumes include alfalfa, red clover, white clover, and birdsfoot trefoil. Legumes fix nitrogen from the air, so they need little or no nitrogen fertilizer. They are higher in protein and calcium than grasses. Alfalfa is the gold standard for dairy forage because of its high protein, high mineral content, and high intake potential.

The main advantage of legumes is protein. Alfalfa at the right maturity tests 18 to 22 percent crude protein. This reduces the amount of expensive soybean meal you need to buy. Legumes also have lower NDF than grasses at the same maturity, which means cows can eat more of them. Higher intake translates directly to more milk.

Legumes have a faster rate of fiber digestion than grasses. This is important for high producing cows because it allows them to eat more total dry matter. A ration built on high quality alfalfa supports higher dry matter intake than the same ration built on grass hay, even if the protein and energy values are similar.

The disadvantages of legumes are agronomic. Alfalfa is not easy to grow. It needs well-drained soil with a pH above 6.5. It is susceptible to winterkill, especially on heavy soils. It is also harder to dry for hay because the stems are thick and the leaves dry faster than the stems. This leads to leaf shatter and quality loss. Alfalfa also has a higher calcium content than grasses, which must be balanced in the ration, especially for dry cows.

Red clover is easier to establish than alfalfa and tolerates wetter, more acidic soils. It does not dry as well as alfalfa, but it is more forgiving of less than perfect management. Red clover also contains an enzyme that reduces protein breakdown during ensiling, which means it preserves protein well in silage. The downside is that red clover has a lower yield than alfalfa and is a shorter lived perennial.

Grasses for Dairy Cows

Grasses include orchardgrass, tall fescue, ryegrass, timothy, and bromegrass. Grasses are lower in protein and calcium than legumes, but they have their own advantages. Grasses are easier to establish and manage than legumes. They tolerate a wider range of soils and pH levels. They are also more winter hardy in many regions.

The main advantage of grasses is energy density when harvested young. A grass cut at the boot stage can have very high digestibility and energy content. Grasses also have a more consistent fiber digestibility across cuttings than legumes. The fiber in grasses is physically different from legume fiber. It provides good effective fiber for rumen health.

Grasses are excellent for dry cows and heifers. The lower protein and calcium content is actually an advantage for dry cow rations, where excess protein and calcium can contribute to metabolic problems at calving. Grass hay is also a good choice for late-lactation cows that need to gain condition without getting too much energy.

The disadvantages of grasses are lower protein and lower intake potential. A grass hay at the same maturity as alfalfa will have 3 to 5 percentage points less protein. You will need to buy more supplemental protein. Grasses also have higher NDF at the same maturity, which limits dry matter intake. For high producing cows, grass alone usually cannot support the intake needed for peak production.

Grass quality declines rapidly with maturity. A grass that is cut at the right stage is excellent. The same grass cut two weeks later is nearly worthless for lactating cows. The window for cutting high quality grass is narrow. You must be ready to move when the crop reaches the right stage.

Choosing Between Them

For a lactating cow ration, legumes are usually the better base. The higher protein and lower NDF support more milk. Most dairy rations in North America are built around alfalfa or alfalfa-grass mixtures. A mixed stand of alfalfa and orchardgrass combines the protein of the legume with the fiber and yield of the grass. This is often the best of both worlds.

For dry cows and heifers, grasses are often the better choice. The lower energy and protein reduce the risk of overconditioning and metabolic problems. Grass hay is also cheaper per ton in most markets.

For organic operations, legumes are especially valuable because they provide nitrogen to the soil without purchased fertilizer. A legume-grass mixture is the foundation of most organic dairy forage systems.

Here is a practical rule. If you need to support high milk production and you have good soil, grow alfalfa or an alfalfa-grass mix. If your soil is wet, acidic, or poorly drained, grow grasses or red clover. If you are feeding dry cows and heifers, grass is your best value. If you are buying forage, buy the quality that matches the production stage of the cows you are feeding.

Matching Forage Quality to Production Stage

Dairy cows have different nutritional needs at different stages of lactation. A one-size-fits-all forage program wastes money and hurts production. The highest quality forage should go to the cows that need it most. Here is how to match forage quality to production stage.

Fresh and High Producing Cows

Cows in the first 100 days of lactation are the most demanding. They are producing the most milk and often cannot eat enough to meet their energy needs. They are in negative energy balance and are mobilizing body fat to make up the difference. These cows need the highest quality forage you have.

For fresh cows, look for forage with crude protein above 19 percent, NDF below 40 percent, and NDFD above 50 percent. Alfalfa haylage at 40 to 45 percent dry matter is ideal. Corn silage with high kernel processing and a high starch content provides the energy these cows need. The ration should be about 50 to 55 percent forage on a dry matter basis, with the rest coming from grains and byproducts.

The key for fresh cows is to maximize dry matter intake. Every extra pound of dry matter intake supports about 2 pounds of milk. High quality forage is the most reliable way to increase intake. If your forage is mediocre, your fresh cows will peak lower and persist less. The entire lactation curve shifts down.

Mid-Lactation Cows

Cows in mid-lactation, from about day 100 to day 200, are past their peak and are slowly declining in production. They are also starting to regain body condition. These cows can use slightly lower quality forage than fresh cows. Forage with 17 to 19 percent crude protein and 40 to 45 percent NDF is acceptable.

Mid-lactation cows are more forgiving of forage variation. They have higher intake capacity than fresh cows, so they can compensate for lower quality feed by eating more. This is the stage where you can feed your second cutting or your lower quality first cutting. You can also increase the forage percentage of the ration to reduce feed costs.

Late-Lactation and Low Producing Cows

Cows in late lactation, beyond day 200, are producing less milk and should be gaining condition before dry-off. These cows need a lower energy ration to avoid getting too fat. Forage with 14 to 16 percent crude protein and 45 to 55 percent NDF is appropriate. Grass hay is excellent here.

The goal for late-lactation cows is to maintain milk production while allowing steady body condition gain. Too much energy at this stage leads to fat cows, which have more problems at calving. Lower quality forage is actually an advantage here because it limits energy intake naturally.

Dry Cows

Dry cows have completely different needs. They need a low energy, low protein, low calcium ration to prevent metabolic problems at calving. Grass hay is the ideal dry cow forage. It provides effective fiber without excess energy or protein. Legume hay is generally too rich for dry cows.

A dry cow ration should be mostly forage. Grass hay at 10 to 14 percent crude protein and 50 to 60 percent NDF is perfect. If you must feed legume hay to dry cows, limit it and blend it with straw or grass hay. Excess calcium in dry cow rations is a major risk factor for milk fever. Legume hays are high in calcium, so they should be limited.

The last three weeks before calving are the transition period. This is when you gradually move the cow from the dry cow ration to the lactating cow ration. Start introducing the lactating cow forages about two weeks before calving. This lets the rumen microbes adjust to the new feeds so the cow is ready to eat a high energy ration immediately after calving.

Step-by-Step Guide to Forage Selection

Here is a practical process for selecting forage, whether you are growing it yourself or buying it.

Step 1: Define Your Herd's Needs

Start with your herd production data. What is your rolling herd average? What is your peak milk? How many cows are in early, mid, and late lactation? Your forage needs are determined by the number of cows in each stage. A herd with many fresh cows needs more high quality forage than a herd with many late-lactation cows.

Calculate your total forage needs for the year. A typical cow eats about 25 to 30 pounds of forage dry matter per day. Multiply that by your number of cows and the number of days you will be feeding stored forage. Add 10 to 15 percent for shrink and waste. This is your annual forage requirement.

Step 2: Evaluate What You Have

Test every cutting and every field. Take samples from multiple bales or multiple locations in the silage face. Send the samples to a reputable forage testing lab. The cost is about 20 to 40 dollars per sample, which is trivial compared to the cost of feeding blind.

When the results come back, sort your forage by quality. Put your highest quality forage in one pile and your lower quality forage in another. This lets you feed the right forage to the right cows. If you are buying forage, ask the seller for a recent test. If they do not have one, take your own sample before you commit to a large purchase.

Step 3: Match Forage to Cow Groups

Assign your forage to your cow groups. The highest quality forage goes to the fresh and high group. Mid-quality forage goes to the mid-lactation group. Lower quality forage goes to the late-lactation and dry cow groups. If you have a one-group system, you need to blend forages to achieve the average quality your herd needs.

If you have a TMR mixer, you can blend different forages to hit your target nutrient values. For example, you might mix high quality alfalfa haylage with lower quality grass hay to achieve a target NDF. This is the most flexible system because you can adjust the blend as forage quality changes through the year.

Step 4: Balance the Ration

Work with your nutritionist to balance the ration around your forage. The forage analysis gives you the base. Your nutritionist adds grains, proteins, minerals, and vitamins to meet the cow's requirements. The forage quality determines how much grain you need. Higher quality forage means less purchased feed.

Review the ration whenever you change forages. A new cutting of hay can test significantly different from the previous cutting. Every time you open a new silo or start feeding a new lot of hay, get a test and adjust the ration.

Step 5: Monitor and Adjust

Watch your cows. Milk production, milk fat, body condition, manure consistency, and rumen fill all tell you whether the forage is working. If milk fat drops, the forage may be too finely chopped or the ration may not have enough effective fiber. If manure is loose and foamy, the cows may be getting too much starch or the forage may be too wet.

Check body condition scores monthly. Cows should not lose more than one condition score in early lactation. If they are losing too much, increase forage quality or energy density. If they are gaining too much in late lactation, reduce energy.

Common Mistakes in Forage Selection

Every dairy producer makes forage mistakes. Here are the most common ones and how to avoid them.

Cutting Too Late

The most expensive mistake in forage production is cutting too late. Every day of delay past the optimal harvest stage reduces digestibility and intake. A one-week delay in alfalfa harvest can reduce milk production by 3 to 5 pounds per cow per day. The yield increase from late cutting does not compensate for the loss in quality and the higher grain bill.

The solution is to put harvest timing at the top of your priority list. Scout your fields regularly. Cut alfalfa at bud stage, not full bloom. Cut grass at boot stage, not full head. If you cannot harvest all your acres at the right time, cut the fields you will feed to your high producing cows first.

Ignoring Forage Tests

Feeding without a forage test is like driving with your eyes closed. You might get where you are going, but you will probably crash. Forage varies from field to field and cutting to cutting. The only way to know what you are feeding is to test.

Make a commitment to test every cutting. Test every load of purchased forage. Keep a record of the results so you can track quality trends over time. This record will help you make better harvest decisions next year.

Feeding the Same Ration to All Cows

Cows at different stages of lactation have different needs. Feeding a single ration to the whole herd means you are either overfeeding your dry cows or underfeeding your fresh cows. Both are expensive.

If you cannot manage multiple groups, at least separate your dry cows from your lactating cows. Dry cows need a completely different ration. Feeding a lactating cow ration to dry cows is a recipe for milk fever, ketosis, and fat cow syndrome.

Switching Forages Abruptly

Cows are creatures of habit. The rumen microbes that digest your forage are specific to that forage. When you switch from one hay to another, the microbial population needs time to adjust. An abrupt switch can cause a drop in intake, a drop in milk, and digestive upset.

When you change forages, blend the old and new over 7 to 10 days. Gradually increase the proportion of the new forage while decreasing the old. This gives the rumen time to adapt.

Buying on Price Instead of Quality

Forage is priced per ton, but you should think about it per pound of energy or protein. A cheap hay that is low in digestibility can cost you more in grain and lost milk than a more expensive hay that is high quality. Calculate the cost per pound of NDF or per megacalorie of energy to compare forages fairly.

Here is an example. Hay A costs 200 dollars per ton and tests 55 percent NDF. Hay B costs 250 dollars per ton and tests 40 percent NDF. On a dry matter basis, Hay A costs 11 cents per pound of NDF. Hay B costs 15 cents per pound of NDF. Hay A looks cheaper, but it will support less intake and less milk. The true cost is in the lost production, not the price per ton.

Storing Forage Poorly

Even the best forage loses quality with poor storage. Hay stored outside loses dry matter and nutrients. Silage that is not packed properly spoils. The money you save on storage is lost many times over in feed shrink.

Invest in good storage. Build a hay barn or at least store bales on a crushed rock pad with good drainage. Cover outdoor stacks with a tarp. Pack silage bunkers properly, cover them with plastic, and weight the plastic down. A few hundred dollars in plastic and gravel saves thousands in feed quality.

Decision Thresholds for Forage Quality

Here are practical thresholds to guide your forage decisions. These are starting points, not absolute rules. Use your forage test and your cows as the final judge.

Forage Test Targets for High Producing Herds

For lactating cows in early lactation, look for these values in your primary forage.

• Crude protein above 18 percent
• NDF below 42 percent
• ADF below 32 percent
• NDFD above 50 percent
• RFQ above 150

If your forage falls below these targets, you will need to increase grain and protein supplementation to maintain production. At some point, the cost of supplementation exceeds the cost of buying better forage.

When to Buy Higher Quality Forage

If your forage tests below 15 percent crude protein or above 50 percent NDF, it is not going to support high milk production. You have three options. Feed it to dry cows or heifers. Blend it with higher quality forage. Or sell it and buy better forage.

The decision to buy forage is a math problem. Compare the cost of purchased forage plus its expected production response against the cost of feeding more grain with your lower quality forage. In most cases, high quality purchased forage is cheaper than the grain needed to compensate for low quality forage.

When to Cull a Forage Source

If you buy forage from a particular source and it consistently tests below expectations, stop buying from that source. If your own fields consistently produce low quality forage, the problem is usually harvest timing or soil fertility. Test your soil and adjust your fertility program. Review your harvest schedule and make cutting date a priority.

Monitoring and Recordkeeping

Good forage management requires good records. You cannot improve what you do not measure. Here is a system for tracking forage quality and cow performance.

Forage Inventory Records

Keep a simple spreadsheet or notebook with the following information for every cutting and every purchased load.

• Field or source
• Harvest date
• Crop and variety
• Forage test results (DM, CP, NDF, ADF, NDFD, RFV, RFQ, minerals)
• Storage location
• Tons stored or purchased
• Cost per ton

This record tells you what you have and what it is worth. It also helps you compare years and identify trends.

Cow Performance Records

Track the following measures monthly.

• Milk production per cow
• Milk fat and protein percentage
• Body condition scores
• Dry matter intake
• Incidence of metabolic disease (ketosis, milk fever, displaced abomasum)

Compare these measures to your forage quality. If milk fat drops when you switch to a new forage, that forage is the likely cause. If ketosis increases in early lactation, your forage may be too low in energy or your cows may not be eating enough.

Ration Records

Record every ration change. Note the date, the reason for the change, and the expected effect. This helps you evaluate whether ration changes achieved their goals. It also helps your nutritionist make better recommendations.

Visual Observations

Some of the best monitoring is simply watching the cows. Look at these signs daily.

• Rumen fill. Cows should have a full, round rumen on the left side. A hollow rumen means intake is too low.
• Manure consistency. Normal dairy manure is a loose pile with a slight dimple. Very loose, foamy manure suggests acidosis. Very dry, firm manure suggests low intake or low digestibility.
• Cud chewing. Cows should be chewing their cud when resting. If many cows are not chewing, the ration may lack effective fiber.
• Body condition. Look at the tailhead and loin area. Cows should maintain condition through lactation, not lose or gain rapidly.

When to Call a Veterinarian or Extension Agent

You do not need a professional for routine forage decisions. But there are times when expert help pays for itself.

Call your veterinarian if you see a pattern of metabolic disease. Multiple cases of ketosis, milk fever, or displaced abomasum in a short period indicate a ration problem. Your veterinarian can examine affected cows and work with your nutritionist to correct the issue.

Call your veterinarian if cows are not eating. A sudden drop in dry matter intake across the herd is an emergency. It can indicate a forage problem such as mold or mycotoxins. It can also indicate an infectious disease. Do not wait to see if it resolves on its own.

Call your extension agent or state forage specialist if you have questions about forage production. They can help with variety selection, soil fertility, harvest timing, and storage. They can also help you interpret forage test results and compare your forage quality to regional averages.

Call your extension agent if you are considering a major change in your forage system, such as switching from hay to silage or adding a new crop to your rotation. They can provide local data on yields, costs, and management requirements.

Call your nutritionist before you make any significant ration change. A good nutritionist keeps up with the latest research and can help you avoid expensive mistakes. The cost of a nutritionist is far less than the cost of a ration error.

Frequently Asked Questions

How often should I test my forage?

Test every cutting and every new storage structure. If you buy hay, test each load or at least each lot from the same field. Forage quality varies with weather, soil, and harvest conditions. One test per cutting is the minimum for responsible feeding. If you are feeding a high producing herd, test more often, especially when you open a new silo or start feeding a new lot of hay.

Can I feed only hay and no silage to high producing cows?

Yes, you can feed all hay and still support high production if the hay is excellent quality. The challenge is that hay quality is harder to preserve than silage quality. Leaf shatter and weather damage reduce quality. If you feed all hay, you need to be especially careful about harvest timing and storage. Most top herds feed some silage because it preserves quality better and supports higher dry matter intake.

What is the best forage for a small dairy herd of 30 cows?

For a small herd, flexibility and storage are the main concerns. Dry hay is often the most practical because it stores well and can be purchased in small quantities. Small square bales are easy to handle and portion. If you make your own forage, consider haylage in bags or tubes, which are sized for small herds. Avoid large bunkers, which are hard to fill and feed out with a small herd.

How do I compare the value of different hays?

Use the forage test, not the appearance. Calculate the cost per pound of dry matter, per pound of crude protein, and per megacalorie of net energy. A hay with a higher price per ton can be a better value if it has higher protein and digestibility. Also consider the RFV or RFQ index for a quick comparison. Ask your nutritionist to help you compare hays on a nutrient basis.

Should I feed legumes or grasses to my dry cows?

Feed grasses to dry cows. Grass hay is lower in energy, protein, and calcium than legume hay. This reduces the risk of milk fever and overconditioning. If you only have legume hay, blend it with straw or a low quality grass hay to dilute the calcium and energy. Dry cows do not need high quality forage. They need the right balance of fiber and minerals.

What is the ideal dry matter for haylage?

The ideal dry matter for haylage is 40 to 50 percent. At this moisture, the crop packs well, ferments properly, and has good feedout characteristics. Haylage that is too wet, below 35 percent dry matter, produces a clostridial fermentation with poor intake. Haylage that is too dry, above 55 percent dry matter, does not pack well and is prone to heating and mold.

How can I tell if my silage is spoiled?

Spoiled silage has a distinct appearance and smell. It is brown or black, has a musty or putrid odor, and is often hot to the touch. It may have visible mold. Do not feed spoiled silage to dairy cows. It can contain mycotoxins, clostridia, and other pathogens that cause serious illness. Remove spoiled silage from the face and discard it. If you see significant spoilage, review your packing and sealing procedures.

What should I do if my cows drop in milk fat after a forage change?

A drop in milk fat is usually a sign of low effective fiber or acidosis. Check the particle size of your forage. If it is chopped too fine, the cows are not getting enough effective fiber. Check the starch content of the ration. Too much starch can drop rumen pH. Blend in some longer forage or reduce the grain. If the problem persists, work with your nutritionist to rebalance the ration.

Related Farming Guides

This section will be populated with links to related farming guides on dairy cattle nutrition, forage production, and herd management. Check back for updates.

Related Clinical & Scientific Guides

• Evaluating Feed Additives for Dairy Cow Performance
• Dairy Barn Fire Safety: Design and Prevention Measures
• Dairy Cow Pregnancy Loss Records and Review

References

• National Mastitis Council: https://www.nmconline.org/
• USDA APHIS Dairy Cattle Health: https://www.aphis.usda.gov/livestock-poultry-disease/cattle
• FAO Dairy Production and Products: https://www.fao.org/dairy-production-products/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.