How to read a silage lab report

Before anything else: which basis is the number on?

This is where most misreadings happen.

A silage report normally prints two columns: as received (also called as-fed, as-sampled, or as-is) and dry matter basis (DM basis, %DM). The as-received column includes the water. The dry matter column strips the water out.

Corn silage is roughly two-thirds water. So a starch figure of 11% as received and 33% on a DM basis are the same silage. If you compare one supplier's as-received number against another's DM number, you will draw the wrong conclusion every time.

Rule: compare everything on a dry matter basis. The only number that belongs on an as-received basis is dry matter itself.

To convert: DM basis = as-received value ÷ dry matter fraction. A silage at 33% DM testing 11% starch as received is 11 ÷ 0.33 = 33.3% starch on a DM basis.

Mycotoxin results add a third basis, which is covered further down. Fermentation acids are almost always reported on a DM basis.

Why dry matter also decides what you actually paid

Silage is sold by weight, and most of that weight is water. At the same price per tonne:

• 1 tonne at 30% DM delivers 300 kg of dry matter
• 1 tonne at 35% DM delivers 350 kg of dry matter

That is about 17% more feed for the same money. Whether you buy by the tonne or by the maund (40 kg), the price only means something once you divide it by the dry matter. A 60–70 kg bale is 1.5–1.75 maunds of wet weight, but what your animals eat is the dry matter inside it.

---

Reference table: corn silage benchmarks

General industry and published values for well-made corn silage. Sources are listed at the end of this page. All values are on a dry matter basis unless stated.

---

The composition numbers

Dry matter and moisture

Dry matter is everything that is not water. Moisture is 100 minus DM. It is the single most important number on the report because it governs the fermentation, the storage life, the freight economics and the price.

Maize is normally harvested for silage when the milk line on the kernel sits between one-third and two-thirds down from the crown — the visible boundary between hardened starch above and milky liquid below, which moves toward the tip as the grain fills. At around half milk line, whole-plant moisture is typically about 66%, i.e. roughly 34% DM. Feedipedia gives 30–35% DM as the most common ensiling window for maize silage; Penn State Extension gives a 32–38% target with 30–40% workable.

Below about 30% DM: effluent runs, soluble nutrients leach out, and clostridia have the conditions they want. Cumberland Valley's commercial dataset shows the fermentation becoming progressively more extensive as silage gets wetter: total fermentation acids rise from about 6.4% of DM in silage at 38% DM to about 10.5% of DM in silage below 26% DM. That is more of the crop's sugar burnt inside the silo and higher dry matter loss — not a better preserve.

Above about 40–42% DM: the crop is hard to pack, air is trapped, fermentation is restricted, and the silage is prone to heating when it meets air again. Kung and Shaver note that corn silage seldom has a pH above 4.2, and when it does, the cause is often silage over 42% DM, over-mature or drought-stricken.

One caveat on the DM figure itself. Most labs determine DM by oven drying. Oven drying volatilises fermentation acids and alcohols along with the water, so oven DM reads lower than true DM, and the gap widens as silage gets wetter and more heavily fermented. Kaiser and co-workers compared eight methods and found Karl Fischer titration and saponification returned higher DM values than oven drying, with the difference increasing as DM content fell. Practically: if two labs disagree on DM by a point or two, the drying method may be the whole explanation.

Crude protein

Crude protein is total nitrogen multiplied by 6.25. Maize silage is a low-protein, high-energy forage; published means sit around 6.9–8.8% of DM, with Penn State's benchmark range at 6.5–8.5%. Nobody buys corn silage for its protein.

The important point is that crude protein tells you nothing about protein quality. A silage that has undergone heavy proteolysis in the clamp still shows the same total nitrogen — the nitrogen has just been converted into ammonia, amines and free amino acids, which are worth much less to the animal. To see that, you need the ammonia-N figure, not the CP figure.

A crude protein result that is unusually low and paired with unusually high fibre is a warning. Ward and de Ondarza describe exactly this pattern in a very wet corn silage sample: moisture had moved through the mass and leached out the soluble material, leaving a sample with 4.4% CP and 57.7% NDF that would feed poorly. That is a sampling-location problem as much as a silage problem.

Starch

Starch is the grain. It is where most of the energy in corn silage comes from, and it is the parameter that separates a properly grown, properly timed maize crop from cut fodder.

Benchmarks: Penn State Extension gives 30–40% of DM as the optimal range and reported a 2025 Pennsylvania harvest average of 34.8 ± 3.67%. Feedipedia's maize silage mean is 29.1% with a range of 16.8–40.6%.

Low starch means one of a small number of things: the crop was cut before the grain filled, the grain filled badly (heat, drought, pollination failure, poor nutrition), or the harvest took a very high proportion of stover relative to cob. Starch and NDF move in opposite directions, so a low-starch silage almost always shows high NDF.

Starch content is not the same as starch availability. See starch digestibility below.

NDF, ADF and lignin

These are the fibre fractions, measured by the detergent system.

• NDF (neutral detergent fibre) is the total cell wall: hemicellulose, cellulose and lignin. It is the fraction most closely tied to rumen fill and therefore to how much the animal can physically eat.
• ADF (acid detergent fibre) is cellulose and lignin. It is inversely related to digestible energy, and most energy equations on your report are derived from it.
• Lignin is the indigestible structural polymer. It is the ceiling on fibre digestion.

Published corn silage values: NDF around 44% (range 37.5–54.7%) in Feedipedia's dataset; Penn State's older production guide gives a desired range of 41.3–54.1%; Penn State's current metrics page gives 30–45% as optimal with a 2025 Pennsylvania average of 34.6%. That spread is not an error — modern hybrids with a higher grain share dilute the fibre, so newer datasets run lower. Judge a result against a recent benchmark, and always alongside the starch figure.

You may see aNDF or aNDFom on the report. aNDF is amylase-treated NDF (the amylase removes starch that would otherwise be counted as fibre). aNDFom is additionally ash-corrected — the residual mineral is subtracted. If a silage is soil-contaminated, uncorrected NDF is inflated by that soil. Where both are available, aNDFom is the cleaner number.

NDF digestibility, uNDF240 and starch digestibility

These are the digestibility measures, and they are the reason a modern report is worth more than an old one. Two silages can have identical NDF and behave completely differently.

• NDFD 30 h — the proportion of NDF digested in 30 hours of in-vitro incubation. Penn State's benchmark is above 55% of NDF; the 2025 Pennsylvania average was 58.2%.
• uNDF240 — the fibre still undigested after 240 hours. This is the truly indigestible fraction. Penn State's benchmark is below 11% of DM; the 2025 Pennsylvania average was 9.9%.
• 7-hour in vitro starch digestibility — how much of the starch is available in the rumen in the first hours. Penn State's benchmark is above 75% of starch; the 2025 Pennsylvania average was 69.2%, i.e. below target.

Low starch digestibility usually points at kernel processing. Whole or cracked-but-intact kernels pass through. It also rises with storage time as the protein matrix around the starch granules breaks down — a silage tested at three weeks will read lower than the same silage at four months.

Incubation times and grind sizes differ between laboratories, so these numbers are only comparable within one lab's method. Ask which method was used.

Ash

Ash is what is left after the sample is burnt: the mineral fraction. In maize forage itself, ash is modest. Feedipedia's mean is 3.7% (range 2.1–5.4%). Cumberland Valley Analytical Services reported a mean of 4.41% across 40,754 corn silage samples. Penn State's benchmark is below 5.0%, with a 2025 Pennsylvania average of 2.9%.

Soil, by contrast, is essentially all ash. So ash above the normal plant range is a direct measurement of soil contamination, and it is often accompanied by elevated iron. Ward and de Ondarza attribute elevated ash primarily to soil, and list the usual causes: cutting too low, rain splash onto swaths, raking with tines set too low, flooding of the standing crop, and soil picked up during filling or at feed-out.

High ash is not just a dilution problem. Soil carries clostridia and soil-borne yeasts into the crop, which is why high-ash silages tend to ferment badly and go unstable in air. If you see high ash and high butyric acid on the same report, they are almost certainly the same story.

Ash also silently distorts other numbers: it dilutes starch and protein on a DM basis and inflates uncorrected NDF.

---

The fermentation numbers

Good silage is preserved by acid, not by drying. Lactic acid bacteria consume the plant's soluble sugars in the absence of oxygen and produce mainly lactic acid, which drops the pH far enough to stop everything else growing. The fermentation panel on your report tells you how well that went.

Two framing points before the individual numbers:

Fermentation takes months, not weeks. Analysis of 19,185 commercial corn silage samples found that lactic acid, pH and titratable acidity did not reach maximum levels until about four months after ensiling, and acetic acid continued rising until about six months. A report from a sample taken three weeks after ensiling is a snapshot of an unfinished process. Ask when the sample was taken relative to the ensiling date.

A fermentation panel is a report card on how the silage was made. It cannot be used to balance a ration. Its value is diagnostic: it tells you whether the crop was cut at the right moisture, packed and sealed properly, and left alone long enough.

pH

pH measures acidity. For corn silage the typical range is 3.7–4.2, and a commonly stated goal is below 3.9. Penn State gives a final pH of 3.7–4.0.

pH is quick, cheap and widely quoted — and weaker than it looks. Two silages can share a pH and hold very different quantities of acid, because pH depends on the crop's buffering capacity as well as on acid concentration. Maize has low buffering capacity, so it does not take much acid to pull maize to pH 4. Across dry matter ranges from under 26% to 38%, average corn silage pH varied by only 0.14 units while total acids ranged from 10.5% down to 6.4% of DM. The pH stayed still while the acid load halved.

Read pH alongside DM and total acids. A high pH in corn silage is worth investigating; a low pH on its own proves less than most people assume.

Lactic acid

Lactic acid should be the dominant acid. It is the strongest of the silage acids, it does most of the work of dropping pH, and fermentations that route sugar into lactic acid lose the least dry matter and energy.

Targets: 4–7% of DM, and at least 65–70% of total acids. That second figure is the more informative of the two.

Low lactic acid points to restricted fermentation (silage too dry, or cold conditions at ensiling), a sample taken after significant air exposure that degraded the lactic acid, or clostridial activity — clostridia can consume lactate, so clostridial silages are typically low in lactic acid and high in butyric.

Acetic acid

Acetic acid smells of vinegar. Typical corn silage runs 1–3% of DM, with a commonly stated goal of under 2%.

Elevated acetic acid (above roughly 3–4%) indicates a wet, slow, prolonged fermentation — very wet crops, loose packing, slow filling, or high buffering capacity. Energy and DM recovery in such silages are worse than ideal.

One important exception. Silages inoculated with Lactobacillus buchneri deliberately produce more acetic acid, because acetic acid suppresses the yeasts and moulds that cause heating at feed-out. In those silages, elevated acetic acid is the product working, not a fault, and studies have not found the associated intake depression. These silages often also show 1,2-propanediol at 0.2–3% of DM, which is a useful fingerprint. If a report shows high acetic acid, ask whether an inoculant was used before you conclude anything.

There is a related trade-off worth knowing: silages that are very high in lactic acid with minimal acetic acid — the textbook "best" fermentation — are often the least aerobically stable, because lactic acid is a poor antifungal. Some acetic acid is desirable.

Propionic acid

Normally very low. Kung and Shaver give under 0.1% of DM for corn silage; most silages test under 0.15%. Cumberland Valley uses a goal of under 0.5%.

Elevated propionic acid in an untreated silage is an index of a poor fermentation. The other explanation is deliberate: buffered propionic acid preservatives applied at 2–4 lb per tonne of wet forage raise propionic acid to roughly 0.15–0.30% of DM. Propionibacteria-based biological additives generally do not compete well enough in silage to move the number.

Butyric acid — the one that matters most

Butyric acid should be zero. The goal for corn silage is under 0.01% of DM.

Butyric acid is produced by clostridia. Clostridia are soil-borne bacteria that thrive in wet, low-sugar, slowly acidified silage, and they do two damaging things: they ferment sugars and lactic acid into butyric acid, wasting energy and dry matter, and they break down protein into ammonia and amines.

Thresholds worth memorising:

• >0.25% of DM — defined as a fermentation problem
• >0.5% of DM — clear clostridial fermentation, one of the poorest outcomes

Clostridial silage smells of rancid butter and often has an olive-green cast. It typically shows low lactic acid, high ammonia-N, elevated ADF and NDF (because the soluble fraction has been consumed), and reduced palatability. High butyric silages have been implicated in ketosis in lactating cows, and the standard advice is dilution or removal from the ration rather than management around it.

If you take one number off a fermentation report, take this one. It is close to binary: well-made corn silage has none.

Ethanol

Ethanol is a yeast product. Typical corn silage runs 1–3% of DM; good silages generally sit under 1–2%.

High ethanol means yeasts were active, which means dry matter recovery was worse than it should have been and the silage is likely to heat and spoil once it meets air. Above 3–4% of DM, ethanol can cause off-flavours in milk.

Ammonia-nitrogen

Ammonia-N is the direct measure of protein breakdown in the silo. It is the number that crude protein cannot give you.

Targets for corn silage: 5–7% of crude protein, or a goal of under 7% of total nitrogen. Above 12–15% of CP is excessive and indicates a slow pH drop or clostridial action. Commercial corn silage datasets show typical values around 8.5% of total N.

Watch the units. Labs report ammonia three different ways — as a percentage of crude protein, as a percentage of total nitrogen, and as a percentage of DM — and the numbers are not interchangeable. Check the column header before comparing against any benchmark, including the ones on this page.

Higher ammonia is normal in wetter silages, because proteolytic and clostridial organisms are more active there. Loose packing and slow filling also raise it.

A related caution: soluble protein is not a substitute for ammonia-N. Cumberland Valley's data found essentially no correlation between the two (R² under 0.01 in legume forages), meaning the soluble protein test tells you how much protein is soluble but nothing about whether that soluble fraction is intact peptides or degraded ammonia.

Heat-damaged protein (ADICP / ADF-bound protein)

If silage heats — from poor packing, air ingress, or slow feed-out — sugars condense with amino acids in the Maillard reaction and become part of the lignin complex. That protein is no longer available to the animal, and neither is some of the carbohydrate bound with it.

Labs report this as ADICP (acid detergent insoluble crude protein), ADF-bound protein, or ADIN. The widely cited threshold of above 2% of DM indicating excessive heating was established for legume silage; corn silage runs lower, so ask your laboratory for its own reference range rather than applying the legume figure. What you are looking for is a value well above the lab's own norm.

---

Mycotoxins and the limits that actually apply

Maize is a mycotoxin-relevant crop. Aspergillus flavus and A. parasiticus produce aflatoxins in maize, particularly under heat and drought stress in the field and under poor storage conditions afterwards; Fusarium species produce fumonisins, deoxynivalenol (DON) and zearalenone in maize. If you are importing maize silage, or supplying milk into a chain that tests for it, this section is the one with legal consequences.

First: which basis is the mycotoxin result on?

EU feed law expresses mycotoxin limits relative to a feedingstuff with a moisture content of 12%. Silage is roughly 65% moisture. You cannot compare an as-received silage result against those limits directly.

The conversion, in two steps:

1. DM basis = as-received result ÷ dry matter fraction
2. 12% moisture basis = DM basis × 0.88

Worked example. A silage at 33% DM tests 3 µg/kg aflatoxin B1 as received.

• DM basis: 3 ÷ 0.33 = 9.1 µg/kg
• 12% moisture basis: 9.1 × 0.88 = 8.0 µg/kg

Against the EU feed material limit of 20 µg/kg, that passes comfortably. Now run the same silage at 8 µg/kg as received: 8 ÷ 0.33 × 0.88 = 21.3 µg/kg, which fails. The as-received number alone would not have told you either way.

EU: aflatoxin B1 is legally binding

Directive 2002/32/EC on undesirable substances in animal feed sets maximum contents for aflatoxin B1, relative to feed with 12% moisture:

Note that dairy animals get the strictest limit by a factor of four. That is not arbitrary — see the carry-over section below.

EU: guidance values for the Fusarium toxins

Commission Recommendation 2006/576/EC sets guidance values (not binding limits) for feed, again relative to 12% moisture. The entries relevant to maize:

Adult ruminants tolerate fumonisins and DON better than pigs or poultry, which is why the ruminant numbers are the loosest on the table.

Codex: a food standard — and it sets no aflatoxin limit for maize at all

Codex Alimentarius CXS 193-1995, the General Standard for Contaminants and Toxins in Food and Feed, gets cited constantly in forage sales material. It is worth reading what it actually contains.

In Schedule I, the total aflatoxin (B1+B2+G1+G2) maximum levels are assigned to these commodities:

There is no maize entry. Codex sets no total aflatoxin maximum level for maize grain, and none whatsoever for maize silage. If someone has shown you a "Codex limit of 15 µg/kg" for maize or for silage, that is the peanut figure wearing the wrong label.

The one Codex mycotoxin maximum level in Schedule I that bears directly on this trade is the one for milk:

Codex has separately adopted maximum levels for fumonisins and for deoxynivalenol in maize and in cereal grains. Those are food standards, written for grain entering the human food chain, and they carry scope notes excluding material destined for animal feed or for wet milling. Verify any of them against the current consolidated edition of CXS 193 before quoting a number: the standard is amended regularly, and the PDF someone emails you is usually not the live text.

Codex's relevant instrument for feed is not a limit at all. It is a code of practice — CXC 45-1997, on reducing aflatoxin B1 in raw materials and supplemental feedingstuffs for milk-producing animals. Guidance, not a maximum level.

The binding numbers for feed are the EU ones above, plus whatever the importing authority actually applies. Codex is the wrong document to specify silage against.

Gulf / GSO

For consignments moving into the GCC, the Gulf technical regulation on this subject is GSO 841 — "Maximum Limits of Mycotoxins Permitted in Foods and Animal Feeds — Aflatoxins", classified under ICS 67.040. The GSO standards store lists the 1997 edition as Edition 1, approved 15 October 1997, with a status of Historical, which means you should confirm the current revision rather than working from a copy someone emailed you.

Because the applicable edition and the importing authority's applied limit both need verifying at the time of shipment, treat the contract specification as the operative number. Confirm three things in writing before a container moves: which standard and edition the importing authority is applying, which toxins are screened, and what documentation must accompany the consignment. state whether you carry out mycotoxin testing, and if so which toxins, against which limit, and what documentation you are able to supply with a consignment

Why dairy buyers care more than anyone else

Aflatoxin B1 eaten by a dairy animal is metabolised and partially excreted in milk as aflatoxin M1. Zentai and co-workers, reviewing the published literature in Toxins in 2023, report EFSA's estimate of the carry-over rate as 1–2% on average, rising to around 6% in high-yielding cows, with aflatoxin B1 intake and milk yield the dominant factors.

That small percentage is enough to matter, because the milk limits are very low. Codex sets aflatoxin M1 in milk at 0.5 µg/kg. The EU limit, in Regulation 2023/915, is 0.050 µg/kg — ten times stricter.

An illustrative calculation, using published carry-over rates and stated assumptions:

• A cow eats 20 kg DM per day of a total ration averaging 5 µg/kg aflatoxin B1 → 100 µg intake per day
• At 2% carry-over → 2 µg per day appears in the milk
• At 25 kg milk per day → 0.08 µg/kg aflatoxin M1

That result is above the EU milk limit, though well below the Codex one. At 1% carry-over it comes out at 0.04 µg/kg, just under. The margin is thin, which is the whole reason the EU sets a dairy compound feed limit of 5 µg/kg against 20 µg/kg for other cattle. If your milk goes into a chain that tests M1, you test the feed. You do not assume.

---

Sampling: why the report may be describing something other than your silage

A lab result is a measurement of the sample, not of the consignment. If the sample is not representative, everything above is arithmetic performed on the wrong material.

This is not a marginal effect. It is usually the largest source of error in the entire process — larger than the analytical error in the laboratory.

A single grab sample is not evidence

Silage is heterogeneous by nature. Within one clamp, the front and sides differ from the core: Ward and de Ondarza describe a corn silage sample from the front or side of a bunker where moisture had passed through the mass and leached out the solubles, producing a result (4.4% CP, 57.7% NDF, almost no fermentation acids) that described a localised condition and nothing else. In baled silage, every bale is its own silo with its own fermentation, so bale-to-bale variation is real and expected.

Mycotoxins are worse still, because mould growth is patchy rather than uniform. Codex states plainly that "the distribution of aflatoxin is extremely non-homogeneous", and its sampling plans are built around that fact: 100 g increments, aggregate samples measured in kilogrammes, lots above 25 tonnes subdivided, and total test error explicitly decomposed into sampling, sample preparation and analytical variance — with sampling dominating.

One handful, from one place, tells you about that handful.

What a defensible sampling protocol looks like

Following National Forage Testing Association practice and university extension guidance:

1. Define the lot. A lot is material of uniform origin — one field or set of fields, one harvest window, one set of conditions and equipment. Maximum lot size is about 200 tonnes. Material that differs gets sampled and labelled as a separate lot.
2. Take at least 20 subsamples per lot, from different bales or different points, following a predetermined random pattern rather than picking the convenient ones. One or two subsamples will not be representative and will bias the result.
3. Sample below the exposed surface. For a fermentation analysis, sample material that has not been exposed to air — at least 20–25 cm behind or below the face. Air exposure degrades lactic acid and shifts the whole panel.
4. Combine and mix thoroughly, then subsample down to the volume the lab wants — at least half a gallon (about 2 litres) of forage for a wet composite.
5. Freeze immediately and ship chilled, overnight, in an insulated container. Send early in the week so samples do not sit in a depot over a weekend. Fermentation acids and ammonia continue to change in a warm bag.
6. Sample at the right time. For a settled fermentation profile, that means at least four months after ensiling. For what the animals are actually eating, sample at feeding.

If a supplier hands you a lab report, ask how the sample was taken. A report without a sampling protocol behind it is one measurement of one handful.

Wet chemistry vs NIR

Reports are produced by wet chemistry (direct chemical analysis) or by near-infrared reflectance spectroscopy (NIR), which predicts values from a calibration built on wet chemistry results. NIR is fast and cheap and works well for the parameters it is well calibrated for. It is weaker for parameters with narrow ranges or poor calibrations, and mycotoxins in particular are not an NIR job.

Two practical rules:

• Stay with one laboratory when tracking a supplier over time, and focus on differences between results rather than absolute values. Procedures vary between labs and so does interpretation.
• Ask the laboratory for its own average and range for each parameter. A result is only interpretable against the distribution the lab that produced it actually sees.

---

Reading a report end to end

An illustrative example — not any producer's actual result, and not a benchmark. It shows the order to read the numbers in.

The story assembles itself: cut too wet, with soil picked up during harvest or filling. The soil brought clostridia; the moisture and the slow pH drop let them work. They consumed lactic acid and produced butyric acid, and they degraded protein into ammonia. The crude protein number still reads 7.8%, which is why you never stop at crude protein. The pH reads 3.94, which is why you never stop at pH.

Note that no single number condemned this silage. Butyric acid and ammonia-N together did, and ash explains why.

---

What to ask a supplier for

If you are buying silage in any quantity, ask for these before the money moves:

1. A certificate of analysis for the specific lot, not a generic sheet — with the lot defined, and the sampling date and ensiling date both stated.
2. The sampling protocol: how many subsamples, from how many bales, taken where.
3. The laboratory's name and method — wet chemistry or NIR, and which parameters were run by which.
4. The full fermentation panel, not just pH. Specifically lactic, acetic, butyric and ammonia-N, with the units stated.
5. Ash, as your soil-contamination check.
6. A mycotoxin screen where the destination or the herd requires it, with the reporting basis stated (as received, DM, or 12% moisture).
7. For export consignments: the phytosanitary certificate, issued under the IPPC framework by the exporting country's national plant protection organisation, plus whatever conformity documentation the importing authority requires for feed.

And read the report against a recent benchmark for the crop, not against a number someone remembers from a different forage.

---

About Forage International

We breed our own hybrid corn genetics and inbred lines, grow the crop on our own farms in Punjab, harvest at milk-line stage, and chop, bale and wrap ourselves — 60–70 kg bales in multi-layer (6–8 layer) UV-resistant film. We sell silage domestically across Pakistan to dairy and livestock farms, and we are set up to serve export buyers.

state your current export position — whether you are shipping to Gulf or other destinations today or building toward it, and to which markets

your published dry matter range from your own lab results your published starch, crude protein, NDF and ADF ranges your published pH and fermentation panel ranges the name of the laboratory you use and whether results are wet chemistry or NIR which parameters appear on the certificate of analysis supplied with each lot your sampling protocol — bales sampled per lot and how a lot is defined minimum order quantity and lot/batch size link to a sample certificate of analysis if you publish one

If you have a lab report in front of you and want a second read of it, send it over. WhatsApp +92 310 4603311 or email [email protected].

Head office: 52 A3 Johar Town, Lahore. Highlight Research Farm: Bahawalnagar Road, Arifwala 57450.

---

Sources

• Kung, L. and Shaver, R. (2001). Interpretation and Use of Silage Fermentation Analysis Reports. Focus on Forage, Vol. 3, No. 13, University of Wisconsin Extension.
• Ward, R.T. and de Ondarza, M.B. (2008). Fermentation Analysis of Silage: Use and Interpretation. Cumberland Valley Analytical Services / Paradox Nutrition.
• Penn State Extension. Key Forage Quality Metrics for Corn Silage.
• Penn State Extension. Corn Silage Production and Management.
• Feedipedia (INRAE, CIRAD, AFZ, FAO). Maize silage.
• Codex Alimentarius. General Standard for Contaminants and Toxins in Food and Feed, CXS 193-1995, Schedule I (Mycotoxins) and Annexes 1–2 (sampling plans).
• Council Directive 2002/32/EC on undesirable substances in animal feed (consolidated).
• Commission Recommendation 2006/576/EC on the presence of deoxynivalenol, zearalenone, ochratoxin A, T-2 and HT-2 and fumonisins in products intended for animal feeding.
• Commission Regulation (EU) 2023/915 on maximum levels for certain contaminants in food.
• GSO 841:1997, Maximum Limits of Mycotoxins Permitted in Foods and Animal Feeds — Aflatoxins, GCC Standardization Organization.
• Zentai, A., Jóźwiak, Á., Süth, M. and Farkas, Zs. (2023). Carry-Over of Aflatoxin B1 from Feed to Cow Milk — A Review. Toxins 15(3):195. (Carry-over rate reported as EFSA's estimate.)
• Kaiser, A.G., Mailer, R.J. and Vonarx, M.M. (1995). A comparison of Karl Fischer titration with alternative methods for the analysis of silage dry matter content. J. Sci. Food Agric. 69:51–59.
• Utah State University Extension. Forage Sampling Guide for Agronomic Crops.
• National Forage Testing Association, sampling recommendations.