Let’s Talk About… FORAGE

Hay, Silage, Haylage, Straw… What’s the difference?

Close up of grass in a field with trees in the background.

After popping some info about the difference between hay and silage on my Instagram story a while ago, I was surprised at the amount of people who messaged to say they’d always wondered but never liked to ask… When does the child who questions everything they don’t understand, turn into the person who stays quietly confused, for fear of being judged for their lack of knowledge (myself included)? Why do we all feel we have to know everything yesterday?

As my dad is so fond of saying, “every day’s a school day”, and he’s right, you can never know it all. There’s no shame in that, the fun is in the learning. And it’s kind of comforting to know we’re all constantly learning, no matter how much experience you have with something.

I’ve had lots of fun learning all this to create these, and now I can actually say I understand what dad’s talking about when he’s on about adding an additive containing bacteria to speed up the fermentation.

So, I hope this gives you the chance to add a nugget to your trivia knowledge too. I truly believe you shouldn’t have to have any connection to the industry in order to gain an understanding about food production and decode farming jargon. It’s why I created the Farm Dictionary (which I’m absolutely rubbish at telling you about- a resource is only useful if people know about it…), so everyone has the opportunity to find easily accessible answers to their questions, even if they don’t know anyone to ask or don’t feel confident in doing so.

We shouldn’t ever lose that childlike sense of wonder at the big wide world and all the questions yet to be answered, or feel discouraged about seeking them out.

Let’s get into this, then…


  • Cut grass, left to wilt (dry) until it contains around 85% Dry Matter.
  • Then packed into various sized bales, held together with net or bands, to be stored and fed to animals.
    • Dry Matter = What’s left when all the moisture is removed. Fresh grass is about 18% DM, so 82% Moisture.


  • Cut grass, left to wilt for less time, until it contains around 30% to 35% Dry Matter.
  • Packed into bales and wrapped in plastic, or consolidated into a clamp (covered mound), so it ferments and is preserved for animal feed.
  • Higher in Energy and Protein and lower in Fibre than Hay. Can also be made from other forages, e.g. Maize Silage.


  • Cut grass, wilted until it contains anything from 45% to 75% Dry Matter (depending on the requirements of what it’s being fed to).
  • Then packed into bales and wrapped in plastic to ferment and be preserved for animal feed.
  • The middle ground between Silage and Hay, both Dry Matter-wise and nutritionally.


  • The dry stalks/stems of cereal or oilseed plants, left behind after the grains have been removed.
  • Packed into bales at around 85% to 90% Dry Matter and used as animal feed or bedding.
  • Not made from grass. Lower in Energy, Protein and Other Nutrients than Hay.


  • Plant material is firmly packed and sealed into an airtight environment, where the forage continues to respire (wilt) and micro-organisms grow until all the oxygen is used up (usually taking a few hours).
  • Once no oxygen is present (anaerobic environment), fermentation begins- usually lasting a few weeks.
  • Bacteria present on the forage converts sugars in it into Lactic Acid, lowering the pH.
  • The production of Lactic Acid continues until the pH is too low for any bacteria to function (around pH 4).
  • At this pH, the forage is now fermented and remains largely unchanged, with its nutrient content preserved & most bacteria and mould unable to function, for as long as it remains oxygen-free. 

4 thoughts on “Let’s Talk About… FORAGE

  1. As you state haylage comes in many different forms of moisture content. A marketing tool of course, but a reasonable one as horse’s can’t tolerate too much lactic acid and too moist haylage is harmful.
    They began calling some horsehage – not just the Denbi imported stuff. Do you have any idea if there exists a rule at which they can market haylage as horse hage or horse specific/friendly – been curious.
    As a producer of course the price sky rockets even though it is normally sold in small bales so higher packaging costs.

    Liked by 1 person

      1. I didn’t really think they would have a set answer – definitely some grasses are better than others, but I still feel the biggest incentive is the oldest – money. People spend more on their horse’s than other animals. There will be a level at which it becomes too rich in proteins, lactic acid etc but not enough to govern the sales pitch


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