Quick answer: For individually wrapped sorghum-sudangrass baleage, target 40–60% moisture, preferably 50–60%, make a dense bale, and wrap within hours. Frost, drought, and young regrowth create separate HCN and nitrate hazards. Waiting can reduce HCN; nitrate does not disappear. Follow source-specific frost guidance, ferment high-risk baleage for 8 weeks, test it, and have your laboratory and veterinarian interpret the result.
Sorghum-sudangrass can produce useful summer forage when heat slows cool-season grass, but the harvest plan must match the intended use. Grazing, dry hay, chopped silage, and individually wrapped baleage are not interchangeable systems. They use different moisture targets, preservation methods, and toxin controls.
Safety first: Prussic acid (hydrogen cyanide, or HCN) and nitrate are different hazards. Either can kill livestock quickly, and curing or fermentation does not guarantee safety. Test frost- or drought-stressed forage through a qualified laboratory. If animals show labored breathing, excess salivation, staggering, weakness, convulsions, or collapse, stop access to the suspect feed and call a veterinarian immediately. Prussic acid can kill within minutes, so this is an emergency call, not a wait-and-see decision. Ruminants are more susceptible than horses or swine to both hazards; UGA and NDSU note that horses handle dietary nitrate far better and equine nitrate poisoning is rare. Do not read that as clearing this crop for horses: University of Maine Extension says not to graze horses on sudangrass or sorghum-sudangrass hybrids because these crops can cause cystitis syndrome, a serious equine condition unrelated to HCN or nitrate. Move affected animals only as the veterinarian directs; stressful handling can worsen oxygen deprivation.
Choose the harvest by intended use
Decide the feed system before mowing. The same standing crop can be suitable for one use and unsafe or impractical for another.
| Intended use | Harvest or preservation target | Main safety decision |
|---|---|---|
| Grazing | Use state- and crop-specific plant-height, frost, and regrowth rules. There is no fermentation step. University of Maine Extension says not to graze horses on sorghum-sudangrass because of cystitis syndrome. | Animals can select young leaves and regrowth, where HCN risk is greatest. Nitrate concentrates in the lower stalk, so grazing strategies for the two hazards can conflict. UNL says the light-stocking, top-two-thirds nitrate strategy is not appropriate for sorghum species because it encourages selection of the leafy tissue where HCN is highest. For sorghum-sudangrass, use the prussic-acid grazing controls and manage nitrate through testing and the ration. |
| Dry hay | Condition the thick stems and achieve a complete field cure before baling. Do not substitute a universal bale-moisture claim for local hay guidance. | Complete curing can lower HCN, but sources disagree on how dependable that reduction is. Drying does not lower nitrate. Test high-risk hay. |
| Chopped silage | University of Florida IFAS recommends 30–35% dry matter, equivalent to 65–70% moisture, for forage sorghum and says sorghum-sudangrass may need wilting. Chopped forage is packed and sealed as a mass. | After frost, authoritative guidance says wait before chopping, ferment high-risk material for at least 8 weeks, and test before feeding. |
| Individually wrapped baleage | 40–60% moisture, preferably 50–60%; dense, uniform bales sealed in stretch film. Bale density substitutes for the packing used in chopped-silage systems. | Baleage ferments more slowly than chopped silage. Allow 6–8 weeks before normal feedout and use at least 8 weeks for high-risk frosted forage, then test. |
Green chop is a same-day feeding method, not stored silage. Ohio State Extension says to feed green-chopped cyanogenic forage within a few hours and never leave it in a wagon or feed bunk overnight. Frost-damaged green chop can still be toxic, so the source-specific frost waits and testing rules still apply.
The chopped-silage moisture figure is not a baleage target. University of Florida IFAS Extension recommends 30–35% dry matter for forage sorghum silage and explains that chopped forage must be packed tightly and sealed quickly. By contrast, Iowa State forage specialist Shelby Gruss defines baleage as a longer-particle, slower-fermenting product made in wrapped bales at 40–60% moisture.
Use maturity and moisture, not one cutting height
The old shortcut that says never to cut or graze below 18–24 inches combines two different questions. Plant-height rules are mainly grazing and regrowth controls for prussic acid. A mower or chopper cutting-height recommendation addresses nitrate concentrated in the lower stalk. Neither is a universal maturity target for making baleage.
- Choose the use first. Grazing release, green chop, dry hay, chopped silage, and baleage have different rules.
- Harvest before the crop becomes excessively mature and stemmy. Purdue Extension notes that overly mature forage has fewer readily fermentable carbohydrates. Hybrid, planting date, regrowth, and the desired ration matter more than a made-up universal cutting height.
- Measure the forage, not the calendar. Take representative moisture checks across the windrow. The top can look ready while the bottom and thick stems remain much wetter.
- Pause for stress history. Frost, drought, hail, prolonged cloud, cool temperatures, nutrient imbalance, or herbicide injury can alter toxin risk. Do not use appearance or fertilizer history alone to clear the crop.
For baleage, Gruss's Iowa State guidance, republished by Ohio State, gives the broad operating range: 40–60% moisture, with 50–60% preferred. Below 40%, poor fermentation becomes more likely. Above about 65%, seepage and clostridial fermentation risk rise. Purdue identifies 50–60% as the best range for fermentation, while Ohio State uses a narrower 45–55% ideal. These are compatible regional operating targets, not grounds for pretending one exact number fits every crop and wrapper.
Frost and drought decision table
There is no honest universal “wait several days” rule. States publish different intervals because the true endpoint is plant condition: whether the frost was killing, whether protected plants or new shoots remain alive, and whether damaged tissue has dried. Use the guidance for your state and document. Do not average the numbers.
| Situation | Named source | Source-specific action |
|---|---|---|
| Frost in the forecast; before it happens | Maryland, Iowa State, and Ohio State | Pull livestock off sorghum species before the frost. Do not graze on nights when frost is likely; toxic HCN can form within hours, even after a light frost. |
| Any frost; grazing | UNL BeefWatch | Keep livestock out for 5–7 days. Each time a new part of the plant freezes, reset the 5–7-day clock until the whole plant is killed. |
| Sparse tillers or regrowth remain after the wait | Kansas State (September 2025) | Do not treat a completed day count as clearance. Kansas State found that limited regrowth can carry greater HCN risk and may need to remain ungrazed even after a freeze event. Target the small plants or regrowth for testing. |
| Non-killing frost; grazing | Iowa State, Doran (October 11, 2024) | Wait 10–14 days. Do not graze wilted plants, young tillers, or new regrowth. |
| Killing frost; grazing | Iowa State, Doran (October 11, 2024) | Wait up to 5–6 days and until plant tissue has dried. This document defines a killing frost as about 26°F or lower for at least 6 hours and warns that thick stands may not be killed. |
| Killing frost; grazing or green chop | University of Maryland Extension (October 2024) | Wait at least 7–10 days; Maryland says prussic acid does not begin to decline until leaves have dried. |
| Frosted crop intended for silage | Iowa State, Doran; corroborated by Penn State and Ohio State | Wait 5–7 days after frost before chopping. Delay feeding for 8 weeks after ensiling. Analyze high-risk feed before feeding. |
| Drought or growth-stopping stress, with or without heavy N | NDSU Extension V839, University of Maine, and University of Wisconsin | Assume nitrate is possible whenever growth slows or stops. Nitrogen fertilizer, manure, and soils high in organic matter can increase plant-available nitrogen and raise risk, but they are not prerequisites. NDSU notes that not all drought produces high nitrate: some soil moisture is needed for uptake, and nitrate is often high for several days after the first rain as uptake resumes. Test before harvest or feeding. |
Iowa State itself has published more than one frost framework. A newer Iowa crop-management article uses at least 7 days after frost and restarts the clock after another frost, while the Doran article above separates non-killing and killing events. That disagreement is another reason to name the document and condition rather than publishing a fake national rule.
Prussic acid and nitrate are not the same hazard
| Prussic acid / HCN | Nitrate | |
|---|---|---|
| Where risk is greatest | Young, leafy tissue, new tillers, and regrowth; cell damage from frost releases HCN. | Stems, especially the lower portion of the stalk. |
| What raises risk | Young growth, frost, drought, plant injury, and high nitrogen or nutrient imbalance. | Any condition that slows or stops growth while nitrate uptake continues: drought, frost, hail, cool or cloudy weather, and nutrient imbalance. Abundant soil nitrogen increases risk but is not required. |
| Does it dissipate? | Yes, if forage fully cures or ferments, but neither process guarantees a safe feed. | No. Drying and storage do not remove nitrate. Ensiling can reduce it only partly. |
| What waiting accomplishes | Post-frost tissue drying and fermentation can lower HCN. High-risk ensiled feed still needs an 8-week minimum and testing. | Waiting after a drought-breaking rain can allow a growing plant to use nitrate, but waiting after harvest does not make nitrate disappear. Test the feed. |
| Laboratory question | Ask for prussic acid or HCN analysis and follow the laboratory's sample-handling instructions because HCN is volatile. | Ask whether the result is NO3-N or NO3 and whether it is on a dry-matter or as-fed basis before using any interpretation. |
Read the seed tag: low-HCN is not the same as dhurrin-free
Do not manage every summer annual as if it has the same HCN pathway. Identify the planted crop and any johnsongrass contamination before using a frost or grazing rule. Ohio State ranks conventional grain sorghum as high to very high HCN potential, forage sorghum and sorghum-sudangrass as intermediate to high, and sudangrass lower but not risk-free. Johnsongrass is also cyanogenic and can accumulate nitrate.
| Seed tag or field identification | What it means for this decision |
|---|---|
| Conventional forage or grain sorghum | Contains the dhurrin pathway and can release HCN after frost, drought, or tissue damage. Grain sorghum generally carries the higher HCN potential. |
| Conventional sorghum-sudangrass | Still carries meaningful HCN risk, especially in young growth and regrowth. Use the crop-specific 24-inch-plus grazing guidance rather than transferring a lower sudangrass number. |
| Conventional sudangrass | Usually lower HCN potential than sorghum-sudangrass, but not zero. Keep the crop identity attached to every height and frost recommendation. |
| Johnsongrass in the stand | Manage it as a separate cyanogenic and nitrate-accumulating plant; a clean seed tag does not remove weed risk. |
| Low-HCN or reduced-risk wording | Lower potential is not elimination. Unless the tag documents a genuinely dhurrin-free cultivar, retain HCN precautions. |
| Documented dhurrin-free cultivar | Penn State reports that removing the dhurrin-synthesis gene eliminates the HCN pathway. It does not prevent nitrate accumulation, replace baleage preservation controls, or clear sorghum-sudangrass for horses. |
Kansas State's September 2025 update also tells producers to look specifically for dhurrin-free genetics when buying seed. It reported limited availability because the technology had one licensee and that company was liquidating. Verify the actual seed tag and current supply; do not reinterpret an ordinary low-HCN hybrid as dhurrin-free.
Pearl millet and foxtail millet avoid the sorghum dhurrin-to-HCN pathway, but they can still accumulate nitrate. Foxtail millet is also not horse forage: University of Kentucky Extension identifies setarian toxicity and seedhead injury, while University of Minnesota Extension warns that foxtail seedheads can embed in a horse's mouth and gut, especially when baled in hay.
What curing does to HCN: disclose the disagreement
Several Extension sources quantify substantial HCN loss during complete curing. UNL reports 50% or more. Penn State and Maryland report reductions up to 75%. Ohio State says properly cured dry hay is rarely toxic, but says incompletely cured hay should be tested before feeding.
Kansas State's 2025 field work shows why a percentage reduction is not a safety guarantee. Drought-stressed forage-sorghum regrowth remained at lethal HCN levels after drying and room-temperature storage from October into April; standing samples collected through January also remained high enough to cause toxicity. Drying may lower HCN and still leave a lethal finished feed when the starting concentration is extreme.
Kansas State recommends sampling the regrowth or smallest plants that will enter the bale before harvest, then testing the finished forage before feeding. A broad composite of bale cores can miss a small, high-risk patch of tillers or regrowth, so target suspicious tissue as well as the finished lot. Kansas State also warns that limited regrowth can carry greater HCN risk and may need to remain ungrazed even after a freeze event. A completed post-frost wait does not clear a field that still carries sparse tillers or regrowth.
Iowa State's current crop-management guidance takes the more conservative position: it does not recommend haying high-risk sorghum, notes that fall dry-down is difficult, and states that, contrary to past belief, haying does not reduce HCN risk. Thick sorghum-sudangrass stems make that practical objection important. The safe resolution is not to pick the most convenient percentage. Require a complete cure, never assume curing removed nitrate, and test high-risk hay or silage before feeding.
Nitrate can be high without heavy nitrogen
Penn State Extension and University of Georgia Extension explain the toxic sequence: rumen microbes convert nitrate to nitrite; absorbed nitrite converts hemoglobin to methemoglobin, which cannot carry oxygen. That is why acute cases can produce rapid breathing, tremors, poor coordination, blue or purple membranes, chocolate-colored blood, collapse, and death. Pregnant animals are held to a stricter standard: UGA and NDSU limit pregnant animals to a smaller share of the ration at nitrate levels acceptable for nonpregnant stock and exclude them at higher levels. Nitrate exposure can also cause abortion, including loss that appears days after exposure. Tell the laboratory and veterinarian which animals will eat the feed before any inclusion rate is set.
NDSU explains that nitrate accumulates when plant growth slows or stops. Fertilized plants commonly test higher, but stress is the operative trigger and fertility is a risk amplifier rather than a prerequisite. Purdue documented sorghum-sudangrass at 13,000 and 17,300 ppm NO3 on a dry-matter basis after 75 lb N/acre, drought, rain, and harvest with an 8-inch stubble. That field example is useful because it shows that a moderate N rate and a raised cutter bar did not guarantee safe forage.
Purdue's case report also shows why this page does not reproduce a universal nitrate threshold table. Laboratories and Extension publications use different forms and bases. NDSU publishes the chemically correct conversion:
NO3-N × 4.43 = NO3. Divide NO3 by 4.43 to convert back to NO3-N. Published tables round differently: NDSU's rows work out to 4.43, while Purdue's equivalence table rounds to about 4.35, so expect small mismatches between publications. Confirm whether the report is in ppm or percent and on a dry-matter or as-fed basis. Do not compare an as-fed baleage result with a dry-matter table. Nitrate in drinking water adds to nitrate in feed; NDSU warns that marginal levels in both can cause poisoning, so test stock water too when drought or frost raises concern. Use the interpretation supplied by your laboratory and veterinarian.
For source-attributed interpretation details, use the companion hub: prussic acid and nitrate in baled forage. This sorghum page remains self-contained for the harvest decision; the companion article handles broader crop, water, and laboratory-report questions.
Grazing and regrowth height are not cutting height
Prussic-acid rules for grazing or regrowth
| Source | Grazing or regrowth release | Scope note |
|---|---|---|
| UNL BeefWatch | New growth at least 18 inches in the summary; the body says 15–18 inches. | UNL's own page uses both figures, so this article reports the conflict instead of silently choosing one. |
| Iowa State, Doran | Plant or new regrowth at least 24 inches before grazing. | This is directly stated for sorghum, sudangrass, and sorghum-sudangrass hybrids. |
| University of Maryland | After a non-killing frost, regrowth at least 2 feet or wait 2 weeks. | Maryland applies this to grazing after frost. |
| Ohio State, Sulc | Splits by species: sudangrass 15–18 inches; sorghum-sudangrass 24–30 inches before grazing or green chop. | The only source reviewed that separates the two crops. For this crop, use the sorghum-sudangrass figure rather than transferring the lower sudangrass figure. |
These are grazing and regrowth controls. They are not instructions to set a mower at 18 or 24 inches, and they do not create a universal baleage cutting threshold.
Nitrate-oriented mower or chopper height
NDSU says most plant nitrate is in the bottom third of the stalk and advises raising the cutter bar above 6 inches. UNL warns that haying or green chopping immediately after a freeze can be dangerous because nitrate does not dissipate; it advises waiting 5 days before haying or chopping and using a 6–8 inch cutting height to help mitigate risk. NDSU cites Oklahoma work in pearl millet where the lower 6 inches contained three times the nitrate of the upper plant, but that is a plant-gradient finding, not a guaranteed reduction in finished sorghum-sudangrass feed.
No Extension source reviewed for this update quantifies a guaranteed nitrate reduction from raising cutting height. Leaving the lower stalk can help, but it sacrifices yield and does not clear the feed. Test the harvested forage regardless.
Sorghum-sudangrass baleage workflow
- Confirm the use and stress history. Record hybrid, field, cutting, fertilizer or manure history, drought, rainfall, and every frost. If the crop is high risk, arrange laboratory testing before it reaches the bunk.
- Cut for forage quality, not a universal height. Avoid overly mature, coarse forage with less fermentable carbohydrate. Use the hybrid's agronomic guidance and your ration goal. Apply the separate 6-inch-plus nitrate cutting guidance only when that risk is present.
- Condition and wilt evenly. Thick stems dry more slowly than leaves. Set mower, conditioner, tedder, and rake according to their manuals, and keep rake teeth out of the soil to limit ash and clostridial contamination.
- Measure representative moisture. Bale at 40–60%, preferably 50–60%. Do not rely on the dry-looking top of a heavy windrow.
- Make a dense, uniform bale. Purdue identifies density and consistent shape as core fermentation controls. Ohio State recommends a minimum target of 10 lb dry matter/ft3. Use only your baler's approved wet-forage settings.
- Bind the bale, then seal it. Purdue specifically lists plastic net wrapping as an appropriate bale binding before the outer film. XES sells the inner net-wrap layer; it does not sell the stretch film or replace the wrapper manual.
- Wrap within hours. Use the timing table below. Build harvest capacity around the wrapper, not around how many unwrapped wet bales the baler can leave behind.
- Allow a full fermentation period. Iowa State recommends 6–8 weeks for baleage generally. For frosted or otherwise high-HCN forage, use at least 8 weeks and test before feeding.
Film layers: six minimum, eight when the bale is wet or stalks are coarse
| Source | Published film guidance | How to apply it here |
|---|---|---|
| Iowa State / Gruss, republished by Ohio State | 6 layers minimum; 8 layers may be needed for high-moisture, stalky bales. | Six is the normal minimum. Use eight when the bale is at the wet end of the range or stalks are coarse enough to increase puncture and sealing risk, a common sorghum-sudangrass condition. |
| Mississippi State | Individual bales: minimum 4–6, recommendation 6. In-line systems: minimum 6–8, recommendation 8. | The four-layer floor is not the recommendation for an individual stalky sorghum bale. |
| Purdue | 6–8 layers of good-quality, sunlight-resistant, 1-mil plastic. | Use the film and stretch specifications approved for the wrapper. |
Count coverage, not raw revolutions. University of Kentucky Extension specifies 50% overlap and two layers during each full bale rotation on an individual wrapper. Operationally, count finished coverage over the whole bale: one complete whole-bale coverage pass at 50% overlap produces two layers at each point. An in-line wrapper uses different geometry; Kentucky's six-layer example spaces film edges no more than 5 inches apart with a 30-inch roll, but a higher layer target changes that spacing. Film width, bale diameter, dispenser count, and wrapper design determine the raw revolution or spacing setting. Use the exact wrapper manual to set and verify complete coverage.
Wrap delay: source-specific timing
| Region/source | Published timing |
|---|---|
| Ohio State, Eastern Corn Belt | Within 2 hours is the ideal condition; the same article uses within 4 hours as the practical harvest-capacity goal. |
| Purdue, Indiana | As soon as possible, ideally within 4 hours. |
| Mississippi State, Southern US | No more than 12 hours; spoilage rather than fermentation becomes the concern as delay grows. |
| Iowa State / Gruss, republished by Ohio State | Wrap within 12 hours, with sooner better. |
For planning, target 2–4 hours and treat 12 hours as an outer limit, not a goal.
Store, inspect, test, and feed out safely
- Choose the site before wrapping. Iowa State recommends a shaded, firm, well-drained surface that will not puncture film or collect water.
- Inspect film throughout storage. Patch holes promptly with UV-protected plastic tape supplied or approved by the film provider. Purdue explicitly says not to use duct tape.
- Do not overstack individual bales. Mississippi State sets a maximum of two bales high for single-bale storage.
- Identify risk lots. Keep field, cutting, harvest date, frost or drought history, moisture, and test results tied to the bales. Do not blend an unknown suspect bale into a clean lot.
- Use the feed in time. Purdue recommends using baleage within 1 year; Iowa State prefers 6–9 months for nutritive value, while Mississippi State says intact 40–60% moisture baleage maintains feed value for about 12 months. Once opened, Iowa State says feed within 3–7 days, with faster spoilage in warm weather.
- Remove both plastic film and net wrap before feeding. Open a bale just before use. If film integrity failed, the bale heated, or the forage has visible spoilage or an abnormal odor, set it aside and have the feed evaluated rather than assuming it is safe.
- Treat fermentation quality as a livestock-safety issue. Purdue says proper fermentation reduces the risk of botulism and listeriosis and identifies soil contamination as a contributing risk. Kentucky flags ash above 11% as evidence of dirt contamination and higher clostridial risk. Ask the laboratory for pH and ash with the nutrient panel and have it interpret the result.
- Test the fermentation as well as the ration. Purdue recommends adding pH to a forage-laboratory analysis. Ask the laboratory which baleage sampling protocol, number of cores, toxin tests, and sample handling it requires.
- Analyze the finished fermented baleage before dilution or feeding. Fermentation may reduce HCN and nitrate but does not guarantee a safe endpoint. Send a representative finished-baleage sample after the fermentation period, then have the laboratory, veterinarian, and nutritionist formulate any dilution, inclusion rate, animal-class restriction, or decision not to feed. Do not calculate a ration from a standing-crop sample alone.
For prussic-acid sampling, Maryland Extension recommends collecting mostly leaf material from several field locations, sealing it in a plastic bag to limit HCN loss, refrigerating it, and delivering it promptly. Follow the receiving laboratory's instructions; do not improvise sample handling.
This page is about individually wrapped outdoor bales. It does not provide tower-silo, bunker-entry, or confined-space procedures.
If the crop wraps a roller or stops feeding
There is no defensible cross-model roller adjustment for sorghum-sudangrass. Extension sources support crop-side controls such as correct moisture, dense uniform windrows, reduced soil contamination, and high bale density; they do not publish model-specific roller clearances, stripper settings, or belt adjustments.
If stalks begin winding on a roller or the pickup stops feeding, stop rather than forcing the slug through. Do not reach into the machine or copy a setting from another baler. Disengage power, shut down, isolate stored energy, and clear the machine only as the exact operator's manual requires. Use that manual or the dealer's service information to diagnose mechanical causes.
The field-to-feed checklist
- Choose grazing, dry hay, chopped silage, or individually wrapped baleage before harvest.
- Record drought, rain, frost, fertility, and regrowth history.
- Apply grazing-height and frost rules only to the conditions and sources that publish them.
- For nitrate risk, leave the lower stalk where practical, but do not treat cutting height as a substitute for testing.
- For baleage, target 40–60% moisture, preferably 50–60%, and make dense uniform bales.
- Use at least six complete film layers over the whole bale, and eight when the bale is at the wet end of the range or the stalks are coarse enough to risk puncturing the film.
- Wrap in 2–4 hours when possible and no later than the applicable 12-hour outer guidance.
- Allow 6–8 weeks before normal feedout and at least 8 weeks for high-risk frosted forage.
- Confirm NO3-N vs. NO3 and dry-matter vs. as-fed basis on every nitrate result.
- Test suspicious plants before harvest and the finished fermented baleage before feeding; let the laboratory, veterinarian, and nutritionist set any dilution or feeding plan.
Frequently asked questions
What moisture should sorghum-sudangrass baleage be?
Target 40-60% moisture, with 50-60% preferred. Below 40%, poor fermentation becomes more likely. Above about 65%, seepage and clostridial fermentation risk rise. Chopped sorghum silage is a different system: University of Florida IFAS recommends 30-35% dry matter, equivalent to 65-70% moisture, followed by tight packing and sealing.
How long should I wait after frost before using sorghum-sudangrass?
Use a source-specific rule. UNL says 5-7 days and resets the clock when newly frozen tissue appears. Iowa's 2024 Doran guidance says 10-14 days after a non-killing frost and 5-6 days after a killing frost, until tissue dries. Maryland says 7-10 days after a killing frost. Do not average these intervals.
Can frosted sorghum-sudangrass be made into baleage?
Yes, with controls. Iowa, Penn State, and Ohio State publish a 5-7 day post-frost wait and an 8-week minimum for chopped silage. No source reviewed gives a baleage-specific post-frost interval. Because baleage ferments more slowly, use those figures as minimum transferred guidance, favor the longer end, and test the finished fermented baleage for HCN and nitrate before feeding.
Does curing sorghum-sudangrass as dry hay remove prussic acid?
Drying can reduce HCN, but it can leave lethal levels. Kansas State found drought-stressed forage-sorghum regrowth still lethal after drying and months of storage. Sample small plants or regrowth before harvest and test the finished feed. Iowa State does not recommend haying high-risk fall sorghum, and curing does not remove nitrate.
How do I compare NO3-N and NO3 on a nitrate report?
Multiply NO3-N by 4.43 to convert it to NO3; divide NO3 by 4.43 to convert back. Also confirm whether the result is reported in ppm or percent and on a dry-matter or as-fed basis. Do not compare unlike units or bases. Use the interpretation provided by your laboratory and veterinarian.
Does dhurrin-free sorghum-sudangrass still need nitrate testing?
Yes. A genuinely dhurrin-free cultivar removes the dhurrin-to-HCN pathway, but it does not prevent nitrate accumulation, replace moisture and fermentation controls, or clear sorghum-sudangrass for horses. Verify the exact seed tag: a conventional or low-HCN claim is not the same as a documented dhurrin-free cultivar. Test stressed forage and finished baleage for nitrate before feeding.
How many film layers should I use on sorghum-sudangrass baleage?
Use six complete layers over the whole bale as the minimum and eight when the bale is at the wet end of the range or stalks are coarse enough to risk puncturing film. At 50% overlap, one complete whole-bale coverage pass produces two layers at each point. Follow the exact wrapper manual for revolutions, stretch, film width, and dispenser setup.
What should I do if sorghum-sudangrass wraps around a baler roller?
Stop rather than forcing the crop through. Do not reach into the baler or copy another model's roller, belt, or stripper settings. Disengage power, shut down, isolate stored energy, and clear the machine only as the exact operator's manual requires. Then check crop moisture and windrow uniformity before using the manual or dealer information for mechanical diagnosis.
The XES Netting team manufactures bale net wrap for round balers. We sell the inner binding layer used before stretch film, so this article includes a commercial link where that layer is discussed. We do not sell veterinary, laboratory, or ration services, and we do not claim firsthand experience growing or feeding sorghum-sudangrass. This guide is general educational information, not veterinary or nutrition advice. Source intervals and laboratory interpretations take precedence over this summary.
Sources checked August 16, 2026: University of Nebraska–Lincoln BeefWatch, “Managing Annual Forages After Frost”; Iowa State University Extension, Beth Doran, “Managing Prussic Acid Poisoning After a Frost”, Shelby Gruss, “Sorghum Forage: A Resilient Option With Smart Management”, and “Frosted Forages and Fall Risks”; Kansas State University Extension, “Good News and Bad News on Prussic Acid”; University of Maryland Extension, “Reducing the Risk of Prussic Acid Poisoning”; Penn State Extension, “Warm Season Annuals and Alfalfa After Frost”, “Dhurrin-Free Sorghum-Sudangrass Prevents Prussic Acid Risk”, and “Nitrate Toxicity in Cattle”; NDSU Extension, “Nitrate Poisoning of Livestock”; Purdue Extension, “Baleage Practices for Success” and “Beware - High Sorghum-sudangrass Nitrate Concentrations Reported”; Mississippi State University Extension, “Baleage Production Tips”; Ohio State University Extension, “Avoid Forage Toxicities After Frosts” and “Tips for Making High Quality Baleage”; University of Kentucky Extension, “Avoiding Botulism in Spring Round Baled Silage” and “Foxtail Millet”; University of Minnesota Extension, “Plants That Cause Mouth Blisters”; University of Georgia Extension, “Testing for Nitrates in Your Forages”; University of Maine Cooperative Extension, “Sorghum, Sudangrass and Sorghum-Sudangrass”; University of Wisconsin Extension, “Prussic Acid and Nitrate Toxicity in Sorghums”; and University of Florida IFAS Extension, “Silage Harvesting, Storing, and Feeding.”
Featured photo: Alfalfa round bales by Gary D Robson, licensed under CC BY-SA 3.0, via Wikimedia Commons.
