Silage

Both are conserved forage, but they are preserved in opposite ways. Hay is dried down to around 12 to 15 per cent moisture so it is too dry for microbes to spoil, then stored in the open. Silage is the opposite. Forage is cut while still green and moist, at around 30 to 60 per cent moisture, then sealed away from air in a wrapped bale, pit, bunker or stack, so it ferments. The good bacteria turn the plant sugars into acids that pickle and preserve the feed.

The practical differences matter. Silage keeps much more of the crop's energy and protein and is highly palatable and digestible, which is why dairy and high-production systems love it. But it is heavy, because you are carting water, it spoils within days once opened or if the seal is broken, and it needs equipment to handle. If you want a stable, easy-to-cart feed, choose hay. If you want high-energy, high-moisture feed for production stock and can feed it out promptly, choose silage.

Baleage, also called wrapped bale silage or round bale silage, is silage made by baling forage at a higher moisture content than hay, then tightly wrapping each bale in several layers of stretch film to seal out air so it ferments inside the plastic. It is the most common form of silage traded between farms, because each sealed bale is a self-contained, transportable unit and you don't need a pit or bunker. The key thing with baleage is that the plastic seal is everything. Any hole from birds, vermin, handling or poor wrapping lets air in and spoils that bale, so inspect the film before you buy and handle bales gently. See our silage wrap guide for how film layers affect quality.

The main silages on the market are:

1. Pasture or grass silage, made from ryegrass, clover and mixed pasture. It is the most common baled silage and a good all-round feed for cattle and sheep.
2. Cereal silage, made from oats, wheat, barley or triticale cut green. It is high yielding with good energy and popular for beef and dairy.
3. Lucerne or legume silage, which is higher in protein and valued for milking cows and growing stock.
4. Maize or corn silage, which is high-energy and starch-rich, usually pit or bunker stored, and a staple of intensive dairy and feedlot rations.
5. Sorghum or millet silage, a summer-crop silage common in northern regions.

Each suits different stock and production goals.

Silage is usually priced per tonne or per bale, and comparing offers takes a bit of care because of moisture. As an indicative guide:

1. Pasture or grass silage runs roughly $60 to $160 a tonne as fed, or about $40 to $120 a wrapped round bale depending on size and region.
2. Cereal silage runs around $70 to $170 a tonne.
3. Lucerne silage runs about $90 to $200 a tonne, reflecting its higher protein.
4. Maize silage is often quoted at $60 to $120 a tonne ex-pit as fed, but carries very high energy per tonne of dry matter.

Watch the moisture. A wet silage looks cheap per wet tonne, but you are partly buying water, so the fairer comparison is price per tonne of dry matter, or per unit of energy. Ask for the dry matter percentage and, ideally, a feed test, so you can compare silage against hay on a true feed-value basis. As always, add freight to work out the delivered cost.

Because silage is fermented and sealed, quality depends on how well it was made. Check:

1. Smell. Good silage smells sweet, pickled or slightly yeasty. Avoid anything that smells rotten, rancid, or of ammonia or tobacco, as that signals a bad, butyric fermentation and lost feed value.
2. Look and feel. It should be green to olive or brown, moist and firm, not slimy, slushy or sun-bleached.
3. No mould. White, grey, pink or black mould, especially near the surface or any hole in the wrap, is a health risk and a sign air got in.
4. Dry matter percentage. This tells you how much actual feed you are buying versus water. Typical baled silage is 35 to 50 per cent dry matter.
5. pH. Well-made silage is acidic, around pH 4.0 to 5.0 depending on dry matter. A higher pH suggests poor fermentation.
6. Feed test. A NIR test showing energy, crude protein, fibre and dry matter lets you value it properly and balance the ration.

Ask for a feed test, the make date, and photos of the bales and wrap. Listings without any quality information deserve extra questions.

Dry matter is the percentage of the feed that is not water, so it is the part that actually feeds the animal. Silage is high in moisture, which makes dry matter the single most important number when you buy or compare it. Two examples make the point. One tonne of silage at 30 per cent dry matter contains only 300 kg of actual feed, while one tonne at 50 per cent contains 500 kg. If you pay per wet tonne without checking dry matter, the wetter silage can be far more expensive per unit of real feed even though it looks cheaper. Dry matter also affects fermentation and travel economics, since wetter silage means heavier freight per unit of feed. Always ask for the dry matter percentage and, ideally, price it on a cents-per-megajoule of energy or dollars-per-tonne of dry matter basis.

It varies a lot with moisture, crop and bale size, but as a rough guide wrapped round silage bales typically weigh 500 to 850 kg, and sometimes over 900 kg for wet, dense pasture silage. That is much heavier than a hay round of the same size because of the water content. Large square silage bales can be heavier again. This weight is why silage needs a tractor or loader with the right attachment to move safely, and why freight is costed carefully, since you are carting a lot of water. Always ask the seller for the actual or average bale weight and the dry matter, so you can work out the real feed value and delivered cost.

The golden rule with silage is to feed it out promptly once it is opened, because exposing it to air restarts spoilage within days, which causes heating, mould and lost feed value. Some practical guidance:

1. Open only what you will use, and plan to feed a wrapped bale within a few days of unwrapping, faster in hot weather.
2. Keep a good, tight feed-out face on pits and bunkers so air can't track in.
3. Introduce stock gradually over 7 to 14 days so the rumen adjusts, and provide effective fibre if the silage is very lush.
4. Feed in rings, troughs or on clean ground to limit waste and trampling.
5. Remove spoiled or mouldy portions, and don't feed visibly rotten or mouldy silage, as some moulds produce mycotoxins and can cause listeriosis.

Because of the fast feed-out window, buy silage in quantities you can use over the right timeframe for your herd size.

Silage suits production stock that need high energy and protein in a palatable form, which is why it is a staple in a few systems:

1. Dairy, where pasture, cereal, lucerne and especially maize silage underpin milking rations.
2. Beef backgrounding and feedlots, where silage provides energy-dense roughage for growing and finishing cattle.
3. Sheep, where good-quality silage suits lactating ewes and finishing lambs.

For maintenance-only stock, or where handling equipment is limited, hay, or even straw as a fibre source, is often more practical. Match the silage type to the job, using lucerne or legume for protein, maize or cereal for energy, and pasture for an all-round feed.

No. Don't feed visibly mouldy or foul-smelling silage. Spoiled silage has lost feed value and can carry health risks. Some moulds produce mycotoxins, and poorly fermented or soil-contaminated silage can harbour Listeria, a cause of circling disease and abortion in ruminants, along with a botulism risk if animal carcasses were baled in. Discard the mouldy outer layers, or any bale where the wrap was breached, and never feed silage that smells rotten or of ammonia. If a bale has a small wrap hole, use it first and cut away the spoiled zone. When in doubt, get it tested rather than risk your stock.

Sealed from air, silage keeps for a long time, but exposed to air it spoils fast. Storage depends on the form:

1. Wrapped bales, or baleage, need the plastic kept intact. Stored on a clean, well-drained pad away from trees, fences and vermin, well-wrapped bales commonly keep 12 months and often longer. Check regularly for holes and patch tears with silage tape straight away.
2. Pit, bunker or stack silage, kept well compacted and sealed under weighted plastic, can store for years. The clock only starts once you open the face.

The enemies are air, water, birds, and vermin like mice, rats, possums and crows that pierce the wrap. Site bales where you can inspect them, keep grass down around them, and control pests. Once opened or breached, feed out promptly, as covered in the feed-out question above.

Use a verified agricultural marketplace with secure payment rather than generic classifieds or social media. To protect yourself:

1. Use escrow or secure payment instead of sending deposits by PayID or transfer to strangers.
2. Ask for photos of the actual bales and wrap, bale weights, dry matter percentage, make date, and a feed test.
3. Be cautious of prices well under market, sellers who avoid calls, and pressure to pay fast.
4. Post a Wanted Ad so verified sellers with matching silage come to you.

Because silage quality hinges on how it was made and stored, the make date, wrap condition and a feed test are especially worth confirming. See our blog on avoiding fodder scams for the latest red flags.

Yes. Posting a Wanted Ad is free and is often the best way to source silage, which is more localised and seasonal than hay. It is ideal when you need a particular type such as maize, lucerne or cereal silage, a specific dry matter or quality, a large volume for a dairy or feedlot, or delivery to your district. Verified sellers holding matching stock can respond to you directly.