The Great Debate

We’re not talking about Trump vs Harris.  We’re talking about Hay vs Silage.

This was a topic of debate at our recent confinement feeding workshop near Roma.  It seems many people are turning to silage, but some seem insistent on storing hay. So, what’s the difference?

Hay is usually 70-95% dry matter. The weathering it experiences in the baling process drops the nutrient content. To get the dry matter that it needs to store safely, it is usually baled late (when the plant is in phase three of its growth) and it’s often of lower nutrient density. Then, storage is at the mercy of the elements unless in a shed where fire and mice plagues are uncommon, but can occur.

What does it cost you to put your hay away? If it costs $300/ha to grow the crop, and it costs you $180/ha to bale it, and you get 5 tonnes of DM per ha, it costs $96/tonne of dry matter to make. I do insist, though, that when we do confinement feeding budgets, that you put the market value of the hay on the ration. This is because you could load it onto a truck and sell it to someone else, rather than feed it to the livestock.

Silage, on the other hand, is usually 30-40% dry matter and is can be cut earlier while the plant is moister.  It undergoes a respiration or wilting phase, which we want to be short. A short wilting phase means that the moisture is lost quickly, which minimises changes to the plant quality and the plant sugars are concentrated by the water loss.  It then enters the fermentation phase where oxygen is excluded from the silage and the anaerobic conditions lead to an increase in the lactic acid producing bacteria. This drops the pH rapidly and preserves the fodder.  As long as the silage is cut and stored well and the air is excluded, the silage will last for years with stable nutrient quality. 

The ongoing quality of the silage is dependent on how well it is tarped and protected from the air and the elements. Maintenance of pits and bunkers is important.

Now if you’re putting your silage in wrapped, round bales, I’d also insist that you put the market value of the bales into your confinement feeding rations. However, if you’re putting it into a pit, you really can’t sell it to anyone else, so the value is the cost of production.  My clients tell me this costs anywhere from $25 to $75/tonne of wet matter, so $75-$225/tonne of dry matter.

So, which do you choose? If I got to choose, I’d have a bit of both on hand. 

Hay can be cheaper to make, and easier to put out in a paddock, if that’s how you choose to feed. If you’re purchasing commodities, rather than making it on farm, hay will be your go-to. But hay is harder to store well long-term (sheds, mice, fire), it’s poorer quality and it’s also not chopped. So, if you are going to put it into a TMR it takes a fair bit more chopping and mixing, and therefore time, to get your ration made.

In some cases, silage is cheaper to make, is generally better quality (so you can pay less per MJ of energy of $/kg of CP), is easier to mix into a ration, and is really yummy if made well and very versatile to mix in with other grains.  It’s lower in fibre so they can fit more in, and you can get great production outcomes.

Both hay and silage can vary wildly in quality, you can get good and bad batches of both. So, make sure you put some time and effort into its creation and storage, and always get a feedtest done before embarking on a feeding program.  And remember, the most efficient forage harvester and utiliser is a ruminant, so setting up your farm system to suit your feedbase and using all that good green stuff by grazing while it’s growing is the best way to do it!

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