Who wrote this, and what it is not. XES Netting manufactures bale net wrap. We are not ruminant nutritionists or veterinarians, and nothing here is a ration, a feeding recommendation, or veterinary advice. This page explains what a cattle hay-intake number actually is, and how to turn a number your own nutritionist gives you into a hay inventory plan without a units error. Every figure below is attributed to a named public source next to the claim, with the animal class, forage type and measurement basis where the source states them — and a note where it does not.
Quick answer: there is no single number, and the reason is not hedging.
- For this worksheet, express intake as dry matter, not as the hay you pitch off the truck.
- Oklahoma State University Extension states plainly that "there really is no requirement for feed intake" — it is an estimate, and it moves with body weight, animal class, forage quality, environment, supplement and health. Low-quality, high-fibre forage can physically cap intake.
- Hay demand is not ration demand. Grazing, byproducts and supplement come out first.
- A requirement is not the quantity cattle will actually eat. Ask your nutritionist which one they handed you: NDSU Extension reports that with free-choice access to large quantities of forage, "intake typically will increase by 15% to 20% beyond what is needed to meet requirements" — hay genuinely consumed, not destroyed.
Dry matter and as-fed are two different weights
For ration and inventory calculations, express cattle intake on a dry-matter basis — what is left once the water is removed. Nutritionists use that basis because water carries no nutrients and moisture varies between feeds. The hay you handle is as-fed: dry matter plus the moisture in the bale. Treat a dry-matter intake figure as bale weight and you under-buy — by roughly 13% at 87% dry matter, more on wetter hay. When a source table does not state its basis, as SDSU's table below does not, confirm it before using the figure.
Penn State Extension describes the two columns on any laboratory report — an "as is" or "as fed" column, and a "DM" column with the water removed — and notes the dry-matter column is what allows a fair comparison between feedstuffs (Penn State Extension, Understanding a Hay Analysis; written for horse owners, but the report convention is the same on any forage report). To go from dry matter to as-fed, divide by the dry-matter fraction: 26 lb of dry matter from hay testing 87% DM is 29.89 lb as fed. To go the other way, multiply.
What actually sets intake
Oklahoma State University Extension's circular on beef cattle nutrient requirements — most of its data calculated from the equations in NASEM's Nutrient Requirements of Beef Cattle, Eighth Revised Edition — opens its intake section with a sentence worth reading twice:
"There really is no requirement for feed intake, although an estimate of how much forage and feed an animal will consume is essential when evaluating rations, supplements or predicting animal performance."
— Oklahoma State University Extension, Nutrient Requirements of Beef Cattle
Cattle have requirements for nutrients. Intake estimates how much feed they will eat, which tells you whether a feed can deliver them — a cow eating a lot of poor forage can still be short of energy. What moves that estimate:
- Forage capacity is usually the limit. "Intake in forage-fed cattle is generally limited by the forage capacity of the digestive tract." More digestible forage passes faster, so cattle eat more of it; poor, high-fibre hay does not simply mean "feed more."
- Frame, class and condition all move it. Larger-framed cattle consume more than smaller-framed; lactating cows consume considerably more of the same-quality forage than gestating cows; fleshy cattle consume 2.5% to 5% less than cattle in average to thin condition.
- Cold raises intake; heat lowers it.
- Protein shortage suppresses intake. The equations assume adequate protein: "if the diet is deficient in protein, the presented dry matter intake values are overestimated."
Supplement does not simply add to hay
Ohio State University Extension's fact sheet on supplemental feeds, taking its composition values from NASEM (2016), explains that starch lowers rumen pH, fibre-degrading bacteria become less effective and forage digestion falls — a negative associative effect in which the supplement reduces forage intake or digestibility instead of improving it. It limits starch-based supplements such as corn to about 0.25% of body weight — roughly 3 to 4 lb of corn a day for most mature beef cows — and reports that above about 0.4% of body weight forage intake and digestibility decrease; first-calf heifers are still growing, so the mature-cow translation does not carry across (Ohio State University Extension, AS-1030). Protein supplementation can do the reverse on low-quality forages below about 7% to 8% crude protein, because rumen microbes need nitrogen to digest fibre. Supplement changes the hay number rather than sitting beside it, which is why the worksheet subtracts it.
Animal class and forage quality
SDSU Extension publishes a forage intake guideline table useful precisely because it refuses to give one number — it splits the estimate by cattle type and forage quality:
| Cattle type | Straw and poor forage | Medium quality forage | Excellent quality forage |
|---|---|---|---|
| Growing and finishing cattle | 1.0% | 1.8 to 2.0% | 2.5 to 3.0% |
| Dry mature cows and bulls | 1.4 to 1.6% | 1.8 to 2.0% | 2.3 to 2.6% |
| Nursed cows | 1.6 to 1.8% | 2.0 to 2.4% | 2.5 to 3.0% |
Read across a row and forage quality moves the estimate by more than a full percentage point of body weight; read down a column and animal class moves it too. No cell is "the" answer, and knowing which cell you are in requires a test, because "medium" and "excellent" are laboratory descriptions, not visual ones.
Oklahoma State University Extension splits the same idea by production stage. Its Figure 3 — "dry matter intake, expressed as percent of body weight, of beef cows consuming low quality forage during three different stages of production," sourced to Johnson et al. (2003) — gives late gestation 1.75%, early lactation 2.5% and late lactation 2.1% (Oklahoma State University Extension). Those are explicitly dry matter, explicitly beef cows, explicitly low-quality forage. Neither table covers replacement or first-calf heifers, and OSU states that first- and second-calf heifers need extra energy for growth until they mature at about four years of age, so a mature-cow figure understates them.
The forage test this depends on
Two worksheet inputs — your hay's dry-matter fraction, and the quality deciding which intake estimate applies — come from a laboratory, not from looking at a bale.
Pulling a representative sample
Penn State Extension's guidance is specific: sample in logical lots — bales from the same field on the same day, a later cutting tested separately. Core through the layers: large round bales toward the centre from the curved edge, square bales from the end through the middle. Take at least 10 large bales, or 20 small bales, per lot, mix the cores and send a composite. Choose the lab first, so it can tell you which options to select (Penn State Extension, Sampling Bales for Forage Quality Analysis). Where your laboratory's protocol differs, follow the lab.
Choosing a laboratory, and what to order
Laboratories are not interchangeable. The National Forage Testing Association states that many laboratories "take short cuts that can produce false results on some samples" while certified laboratories "have proven the ability to produce accurate test results on recognized reference methods," and publishes a certified-laboratory list (NFTA, Certification); use a certified lab, or one documenting equivalent method validation. A planning panel gives dry matter (used directly by the worksheet), crude protein, an energy estimate as TDN or net energy for maintenance, and NDF and ADF. Risk-triggered tests are separate, ordered for a specific reason rather than by default:
- Nitrate. NDSU Extension flags nitrate toxicity in stressed small-grain forages, brassicas, millet, sorghum and sudangrass, corn cut for hay, and pastures carrying nitrate-accumulating weeds — after drought or other conditions that inhibit photosynthesis, and where high nitrogen fertiliser rates have been applied. Its recommendation: "test for nitrates prior to grazing or haying." The Nitrate QuikTest "is not designed to evaluate nitrate content in harvested forages"; for baled hay, NDSU directs you to "use a bale probe to collect core samples and submit them to a laboratory for analysis," ideally "10% of bales or at least 20 core samples per lot of forage," a lot being hay harvested within 48 hours from the same field. Nitrate does not decline in stored forage (NDSU Extension); where your laboratory specifies a different protocol, follow the laboratory.
- Mycotoxin. University of Nebraska–Lincoln Extension makes the point you cannot eyeball: mycotoxins are unevenly distributed, and "visibly moldy areas may not contain detectable mycotoxins and visibly mold-free areas may contain high concentrations of mycotoxins." Five to ten pounds are typically submitted, of which only 10 to 50 grams are analysed, so how representative your collection is governs whether the result means anything (UNL Extension, EC3069).
No visual inspection clears hay. Where a lot's growing conditions, weather history or storage give reason for concern, order the test and involve your veterinarian in what to do with the answer.
Bale weight and bale dry matter
A bale count is only as good as the weight you divide by, and nominal bale size is not a weight: two bales of identical dimensions can differ substantially with crop, moisture and baler density. NDSU Extension's instruction is to "use a commercial scale to get a good estimate of bale weight by weighing several loads or multiple individual bales," then to determine dry matter content, "because moisture affects weight but does not provide nutrients to the animal." The same source groups bales by lot — similar species from the same field within a 48-hour period — and says that where dry matter is unknown, 85% to 90% can be used for an initial estimate, with laboratory analysis recommended for ration balancing (NDSU Extension, Now is the time to estimate winter hay needs). Replace the placeholder with your lab number before you commit money.
Feeding loss: what the trials measured
Hay that leaves the stack does not all become nutrition: some is pulled out, trampled, bedded on, fouled or refused. Illinois Extension reproduces two named feeder trials. The first is a Michigan State University trial (Buskirk et al., 2003): four round-bale feeder designs, second-cutting alfalfa and orchard grass testing about 13% crude protein, 53% NDF and 35% ADF on a dry-matter basis, cow weights averaging about 1,385 lb (Illinois Extension, Bale Feeder Design). Illinois's hay-waste article supplies the trial length, two 7-day periods, and states these percentages are dry-matter hay waste (Illinois Extension, Reducing Hay Waste).
| Item | Cone | Ring | Trailer | Cradle |
|---|---|---|---|---|
| Initial cow weight, lb | 1,383 | 1,389 | 1,390 | 1,385 |
| Hay disappearance, lb DM/head/day | 26.4 | 26.6 | 30.5 | 28.3 |
| Hay waste, lb DM/head/day | 0.9 | 1.5 | 3.5 | 4.2 |
| Hay waste, % of disappearance | 3.5 | 6.1 | 11.4 | 14.6 |
| Hay intake, lb DM/head/day | 25.3 | 25.1 | 27.0 | 24.2 |
| Intake as % of cow body weight | 1.8 | 1.8 | 2.0 | 1.8 |
Illinois also reports an Oklahoma State University trial (Lalman) in which four feeder designs gave hay waste as a percentage of bale weight of 5.3% (cone), 13.0% (sheet), 20.5% (ring) and 21.0% (poly), against an assumed 1,200 lb bale. The ring result differs sharply between the two — 6.1% of dry-matter disappearance in one, 20.5% of as-fed bale weight in the other. Different denominators; neither is "the waste number for a ring feeder," and neither denominator is F.
Neither of the two 45% figures quoted everywhere is a clean loss-over-offered number either. NDSU: "if bales are rolled out on the ground, losses due to trampling and overconsumption could be as high as 45%, particularly when cattle are fed for multiple days at one time" — bundling hay destroyed with hay eaten above requirement (NDSU Extension). Illinois: "feeding losses as high as 45% when hay is fed on the ground," which "would also include animal refusal due to other factors such as spoilage" (Illinois Extension).
So disappearance is not the same as waste: hay that vanishes may have been trampled, eaten above requirement, or spoiled, and lumping those into one percentage — then applying it to a requirement — double counts. What the trials isolated was feeder design: 3.5% to 14.6% within Buskirk, 5.3% to 21.0% of bale weight within the Oklahoma trial, about four-fold in each. Bale presentation, animal class, feeding frequency and weather were varied by neither. Do not adopt a published trial number as your input: measure your own operation, and until you have, run the sensitivity range.
The worksheet
| Symbol | Input | Unit | Source |
|---|---|---|---|
| A | Expected total-ration dry matter consumed per head per day, under the routine you will actually run | lb DM / head / day | A qualified ration calculation for your cattle, forage test, conditions and feeding method — not from this page. See below. |
| B | Non-hay dry matter — grazing, residue, byproducts, supplement | lb DM / head / day | Same calculation; what the animal consumes, not what is delivered. |
| C | Hay dry matter to be consumed = max(A − B, 0) | lb DM / head / day | Calculated. If B is at or above A, hay demand is zero. |
| D | Hay dry-matter fraction | decimal (85% = 0.85) | Your laboratory report for that lot. |
| E | Hay as fed that must be consumed = C ÷ D | lb as-fed / head / day | Calculated, before feeding loss. |
| F | Measured feeding loss: dry matter lost as a fraction of dry matter offered | decimal (10% = 0.10) | Measured on the feeder and routine you will use. Not overconsumption, which belongs in A. |
| G | Head in this class | head | Your count. |
| H | Feeding days for this class | days | Your feeding calendar. |
| I | Inventory reserve fraction | decimal (10% = 0.10) | Your decision, on its own line. Weather, access, calendar — not a loss allowance. |
| J | Representative bale weight, as fed | lb as-fed / bale | Scale-measured, not a nominal size. |
- C = max(A − B, 0) lb DM per head per day.
- E = C ÷ D lb as fed — what has to end up inside the animal.
- Hay to offer = E ÷ (1 − F) lb as fed per head per day.
- Season total = offer × G × H × (1 + I), the reserve visible on its own line.
- Bales = total ÷ J, rounded up. Round once, here; never per cow or per day.
The one question to ask before you use A
Is this figure a nutrient-requirement intake, or the intake you expect under my feeding routine? They are not the same number, and the worksheet needs the second. A requirement is how much dry matter an animal must consume to meet its nutrient requirements; what cattle actually consume also depends on how hay reaches them. NDSU Extension reports that "with free choice access to large quantities of forage, intake typically will increase by 15% to 20% beyond what is needed to meet requirements" (NDSU Extension). That hay is eaten, not destroyed, so it is neither loss (F) nor reserve (I): it belongs inside A, or it has no home in the arithmetic and the plan buys short.
Given expected intake under your routine, use it as A unchanged. Given a requirement, A is that requirement plus whatever overconsumption your nutritionist expects from the way you feed — bale ring, bale grazing, several days' hay at once. NDSU's 15% to 20% is scoped to free-choice access to large quantities of forage, not a constant for every plan. Do not add 15% to 20% automatically, and never put it in F or I.
Why step 3 divides rather than multiplies
F is the fraction of the dry matter offered that is lost. Offer X and the animals consume X × (1 − F); you need them to consume E, so X = E ÷ (1 − F). Because D converts the whole offered stream at one dry-matter fraction, dividing the as-fed figure by (1 − F) equals dividing the dry-matter figure and converting afterwards — the two routes in the illustration are one expression. Multiplying by (1 + F) answers a different question, and under-allocates by exactly F² of the offer you should have made: 1% at F = 10%, 4% at F = 20%. Extension worksheets commonly use that markup as a planning margin — NDSU adds 189 bales to a 1,260-bale plan as "1,260 bales × 1.15" — but if E must be consumed, divide.
What must not be double counted
- F and I differ. F is hay delivered and lost; I is hay held because the calendar may run long or a storm may cut off access to a stack.
- Storage loss is a third thing. NDSU notes dry-matter losses of 20% or more outside against around 7% inside. A J measured after storage carries that loss; a J measured at baling does not, and it is then accounted for nowhere. But a post-storage J does not absorb the whole problem: a weathered bale still weighs its spoiled shell, which is disproportionately refused, so F must be measured on those same weathered bales.
- Free-choice overconsumption is a fourth thing, and it lives in A — cattle eating above requirement, not hay destroyed; not F, not I, not storage.
- Normal remnant is inventory, not loss; count it once, on the day it is consumed.
- Supplement is subtracted, not added. B comes out at step 1.
One worked illustration
Illustration only. Every number below is invented and round, chosen to make the arithmetic easy to follow. It is not a ration and not a figure to copy. A and B come from a qualified ration calculation, D and J from measurement, F from your own operation. A of 30.0 is expected intake under the planned routine, not a requirement awaiting an allowance.
Assumed inputs: A = 30.0 · B = 4.0 lb DM/head/day · D = 0.87 · F = 0.10 · G = 60 head · H = 150 days · I = 0.10 · J = 1,150 lb as-fed.
| Step | Arithmetic | Result |
|---|---|---|
| 1. Hay DM to be consumed (C) | 30.0 − 4.0 | 26.0 lb DM / head / day |
| 2. As-fed to be consumed (E) | 26.0 ÷ 0.87 | 29.885057 lb as-fed / head / day |
| 3. As-fed to offer | 29.885057 ÷ (1 − 0.10) | 33.205619 lb as-fed / head / day |
| 4. Head-days | 60 × 150 | 9,000 head-days |
| 5. Subtotal, as fed | 33.205619 × 9,000 | 298,850.57 lb as fed |
| 6. Add reserve (I) | 298,850.57 × 1.10 | 328,735.63 lb as fed = 164.4 tons |
| 7. Bales, rounded once | 328,735.63 ÷ 1,150 = 285.86 | 286 bales |
The same answer by the other route. Usable DM per bale = J × D × (1 − F) = 1,150 × 0.87 × 0.90 = 900.45 lb DM. Total hay DM demand = C × G × H × (1 + I) = 26.0 × 9,000 × 1.10 = 257,400 lb DM. Bales = 257,400 ÷ 900.45 = 285.86 → 286 bales. Both routes give 286 because they are one expression rearranged: C × G × H × (1 + I) ÷ [J × D × (1 − F)]. If your two routes disagree, one input is on the wrong basis. Rounding 285.86 up also buys 328,900 lb against a plan of 328,735.63 lb; record that 164 lb as carryover.
Sensitivity
| Change from the illustration | Total, tons as fed | Bales | Change |
|---|---|---|---|
| Baseline (D = 0.87, F = 0.10, H = 150) | 164.4 | 286 | — |
| Hay dry matter 82% instead of 87% | 174.4 | 304 | +18 |
| Hay dry matter 92% instead of 87% | 155.4 | 271 | −15 |
| Measured loss 5% instead of 10% | 155.7 | 271 | −15 |
| Measured loss 20% instead of 10% | 184.9 | 322 | +36 |
| 135 feeding days instead of 150 | 147.9 | 258 | −28 |
| 180 feeding days instead of 150 | 197.2 | 344 | +58 |
In this illustration, a month either side moves the pile more than any other tested change — a forecasting problem, not a nutrition one. Feeding loss is the biggest controllable input in the ranges shown, with a 51-bale swing between 20% and 5%; five points of laboratory dry matter creates an 18-bale swing.
Two arithmetic traps
Trap 1: rounding at the wrong step
Rounding a per-day or per-head figure up to a whole bale before multiplying carries that rounding into every day of the season. NDSU's inventory example shows the mechanism: the herd needs 6,702 lb of dry matter per day, each bale supplies 1,400 × 0.88 = 1,232 lb, and the article states "around 6 bales would be required to meet feed needs per day, with a minimum of 1,260 bales required for the feeding period" over 210 days. The exact daily figure is 6,702 ÷ 1,232 = 5.44; rounding up to 6 and multiplying by 210 gives 1,260, while rounding once at the season total — 1,407,420 ÷ 1,232 = 1,142.4, rounded up — gives 1,143. That 117-bale difference is 10.2% of 1,143, or 9.3% of 1,260.
Read what the difference is, and is not. It is not permission to buy 117 fewer bales. NDSU says "around 6," calls 1,260 a minimum, then adds a loss factor: "assuming an overall loss of 15%… an additional 189 bales would be needed (1,260 bales × 1.15)" — so NDSU's planned inventory is 1,449 bales, and 1,143 sits 21% below it. The 1,143 is the ungarnished season arithmetic before any margin, not a smaller answer to the same question; that example also applies a flat 2.5% of body weight across mature cows, bulls and yearling heifers alike, which NDSU's own text calls an estimate rather than a measurement. The rule that transfers: round once, at the end, and put your margin on a line you can see.
Trap 2: treating a table figure as a measurement
The intake percentages, feeder-waste percentages and the 85% to 90% dry-matter placeholder are starting points, each with a named scope: a cattle type, a forage quality, a feeder design, a trial length, a measurement basis. Carrying a figure out of its scope is how "1.8% of body weight on 1,385 lb cows eating alfalfa-orchardgrass from a cone feeder over seven days" becomes "cows eat 2.5% of their body weight," which becomes a purchase order.
Mixed classes
Run the worksheet once per class and add the results. Do not average body weights, and do not average classes. Take the illustration's 60 head at C = 26.0 lb DM/head/day and add 15 head of a lighter class at C = 22.0, same 150 days, same 10% reserve, same hay and feeder:
- Class one: 26.0 × 60 × 150 × 1.10 = 257,400 lb DM
- Class two: 22.0 × 15 × 150 × 1.10 = 54,450 lb DM
- Summed correctly: 311,850 ÷ 900.45 = 347 bales
- Blind class average ((26.0 + 22.0) ÷ 2 = 24.0 across all 75 head): 297,000 lb DM → 330 bales
The blind average is 17 bales short because averaging the two per-head figures weights the classes equally even though the heavier class has four times the head count. The direction of that error depends on your class mix. The same discipline applies when a feeding period is split — two rows, two H values, added.
Cold, wet and wind
Cold raises the animal's energy requirement, and whether she can meet it from the feed in front of her is a separate question. The threshold is lower critical temperature, and it moves with coat: SDSU Extension publishes 60 °F summer or wet, 45 °F dry fall, 32 °F dry winter and 19 °F dry heavy winter, adapted from D.R. Ames at Kansas State University, while NDSU Extension states that "generally, a lower critical temperature of 18℉ is used for livestock with dry, heavy coats but -6℉ and calm conditions have been used for well-acclimated animals" (NDSU Extension, Cattle and Cold). For the same coat class the two agree — 19 °F against 18 °F — and NDSU's −6 °F is a different scope, well-acclimated animals in calm conditions.
Both state the same rule of thumb — and neither source's own published table is built on it. SDSU: "a rule of thumb is that energy requirements (TDN) increase 1% for every degree below the animal's lower critical temperature," and NDSU states the same. But SDSU's table moves 15.5 lb TDN at 32 °F to 17.8 lb at −15 °F, about 15% across 47 degrees, and NDSU's example moves 15.5 lb TDN at 30℉ to 17.75 lb at −15℉, about 15% across 45 degrees — both embedding roughly 0.3% of TDN per degree, about a third of the stated rule. This page reports that gap without adjudicating it and does not offer the rule as a formula. Use your nutritionist's cold-adjusted figure, in A.
Cattle do eat more in the cold, and SDSU quantifies it. Its Table 4 gives no impact from 59 to 77 °F, then 2 to 5% more intake at 41 to 59 °F, 3 to 8% at 23 to 41 °F, 5 to 10% at 5 to 23 °F and 8 to 25% below 5 °F, and concludes that this "extra" feedstuff can usually be used by cows to meet the additional energy requirement without changing the ration. Those bands are SDSU's estimate for cattle generally, not scoped to your class, forage or shelter, so they belong in the conversation with your nutritionist about A. The exception is gut fill: SDSU asks whether an animal already consuming 100% of her daily intake can meet the requirement from more forage, and against OSU's point that forage intake is limited by digestive-tract capacity, a cow on low-quality, high-NDF hay in severe cold may face a requirement she cannot eat her way to. That calls for a higher-energy ration designed by someone qualified — and if cattle are losing condition, for your nutritionist and your veterinarian. Both sources note wind protection and bedding; NDSU adds feeding later in the day. For inventory, keep the increase in A, a worst case in H, access risk in I — never in F.
Measuring your own operation
Bale weight (J). Weigh several loads or multiple bales on a commercial scale, across the lots you will feed, recording the date and the moisture reading taken at the same time. One bale is not a sample.
Hay dry matter (D). From the laboratory report on a cored composite for that lot.
Feeding loss (F). The measurement most operations have never made, and the one with the biggest swing:
- Pick one feeder, one group, one hay lot. Mixing feeder types or hay lots inside one measurement gives an average that describes nothing.
- Weigh what goes in, recording the scale weight and date of every bale placed.
- Run a period, not a snapshot. Illinois describes the Michigan State trial as two 7-day periods, and an SDSU study in which gestating cows were fed an average of 58 days.
- Separate the three fates of uneaten hay: trampled and pulled-out on the ground; remnant still in the feeder, which is inventory not loss; and spoiled or fouled hay, loss with a different fix.
- Compute F as dry matter lost ÷ dry matter offered. Take moisture readings on what you put out and what you pick up, and convert both before dividing; as-fed weights are an approximation valid only when lost and offered hay are at comparable moisture, which weathered or fouled material usually is not. Neither trial gives you F — Buskirk reports against dry-matter disappearance, the Oklahoma trial against as-fed bale weight — so measure on the bales you will feed: if J came off the scale after outside storage, F must too. Record feeder design, bale form, animal class, group size and weather.
Feeding days (H). Use your records of when feeding actually started and stopped in previous years, not the calendar you intended. A range in the records is the honest input to the sensitivity table.
Re-check mid-season. Count the stack on a fixed date and compare bales consumed against the plan's rate; if you are running ahead, find out which input was wrong before you are short.
Limits of this page
- This page cannot give you A or B. Those are outputs of a ration calculation for your cattle, forage analysis, production stage, conditions and feeding method — including whether the figure you are given is a nutrient requirement or the intake expected under your routine.
- Nothing here is veterinary advice. Nitrate, mycotoxin, mould, body-condition loss and cold-weather metabolic problems are veterinary matters, as is whether a lot is safe for specific animals.
- The intake and loss figures here are scoped to their trials. They show how wide the range is; they are not your inputs.
- The worked illustration is arithmetic, not agronomy. Its inputs are invented.
- We are a net wrap manufacturer. Where this page conflicts with your nutritionist or veterinarian, they are right.
Frequently asked questions
How much hay does a beef cow eat in a day?
There is no single figure. Oklahoma State University Extension, working from the NASEM equations, states that there really is no requirement for feed intake — it is an estimate used to check whether a ration delivers the required nutrients — and it moves with body weight, animal class, forage quality, environment, supplement and health. It is conventionally expressed as dry matter, not as the hay you handle. Get the figure from a qualified ruminant nutritionist working from your forage test, and ask whether it is a nutrient requirement or the intake expected under your routine: NDSU Extension reports free-choice access to large quantities of forage typically raises intake 15 to 20 percent beyond requirements, hay eaten rather than wasted, so it belongs inside input A.
What is the difference between dry matter and as-fed hay?
Dry matter is what remains after all water is removed, and it is the basis on which cattle intake and nutrient requirements are stated. As-fed is the hay including its moisture — what you load, weigh and pay for. To convert dry matter to as-fed, divide by the dry-matter fraction on your laboratory report; to go the other way, multiply. Twenty-six pounds of dry matter from hay testing 87 percent dry matter is 29.89 pounds as fed. Treating a dry-matter figure as bale weight under-buys hay by roughly 13 percent at that level, and more on wetter hay.
How many bales of hay does a cow need per month?
This page does not give one, because that number is the output of at least six inputs rather than a constant: the hay dry matter need for that animal class, the dry-matter fraction of your hay, your measured feeding loss, the feeding days involved, any reserve you carry, and the measured weight of your own bales, which nominal bale size does not tell you. Run the worksheet above with your own numbers. Any single monthly figure quoted for all cattle has hidden every one of those inputs.
How many tons of hay does a cow need for the winter?
The same answer, for the same reason. A tonnage figure is an output of the worksheet, not an input, and it changes with animal class, forage quality, feeding days, measured feeding loss, hay dry matter and how much of the ration comes from grazing or supplement. In the illustration above, changing only the feeding days from 150 to 180 moves the total from 164.4 to 197.2 tons for the same 60 head — one input moving the answer by a fifth.
Do cattle eat more hay in cold weather?
Yes, generally. SDSU Extension publishes the intake response by temperature band: 2 to 5 percent more at 41 to 59 degrees Fahrenheit, 3 to 8 percent at 23 to 41, 5 to 10 percent at 5 to 23 and 8 to 25 percent below 5 degrees, and concludes the extra feedstuff can meet the additional requirement without changing the ration. The exception is forage quality: intake is limited by digestive-tract capacity, so on low-quality, high-fibre hay in severe cold a cow may not eat her way to the requirement, which calls for a higher-energy ration from a qualified nutritionist. SDSU and NDSU both quote a 1 percent per degree TDN rule of thumb, but neither source's own table is built that way, so this page does not offer it as a formula. Use your nutritionist's cold-adjusted figure in A.
How much hay is wasted at the feeder?
It depends on feeder design, bale form, animal class, feeding frequency and weather. In the Michigan State trial above, dry-matter waste was 3.5, 6.1, 11.4 and 14.6 percent of hay disappearance for cone, ring, trailer and cradle feeders. An Oklahoma State trial reported 5.3, 13.0, 20.5 and 21.0 percent of bale weight for cone, sheet, ring and poly feeders — a different denominator on a different trial. Feeder design alone moved the figure about four-fold within each trial; the other variables were isolated by neither. The 45 percent figures Illinois and NDSU quote for ground feeding are not clean loss fractions — NDSU's bundles trampling with overconsumption, Illinois's includes refusal due to spoilage — so neither belongs in the worksheet as F.
How do I plan hay when I run different classes of cattle?
Run the worksheet separately for each class and add the results. Do not average body weights or classes, because averaging weights each class equally regardless of head count. In the mixed-class example above, 60 head at 26.0 pounds of hay dry matter per day plus 15 head at 22.0 pounds comes to 347 bales when summed correctly, but only 330 bales if the two figures are averaged across all 75 head — a 17-bale shortfall. The size and direction of that error depend on your class mix.
Maintained by the XES Netting team — a bale net-wrap manufacturer, not a nutrition or veterinary practice. Intake, ration and animal-health decisions belong to a qualified ruminant nutritionist and your veterinarian.
Featured photo: Cattle Feeding on Hay by CSIRO, licensed under CC BY 3.0, via Wikimedia Commons. Re-verified against the Wikimedia Commons file record: licence CC BY 3.0, attribution required, artist CSIRO, title "CSIRO ScienceImage 2463 Cattle Feeding on Hay," description "Cattle grazing on hay," source scienceimage.csiro.au/image/2463. That record is the basis of this credit; it does not itself distinguish dry hay from silage or baleage, and this page makes no claim beyond what the record states.
