Crude Ash: The Most Misunderstood Line on Your Horse’s Feed Label

You’ve turned the tub around, run your eye down the analytical constituents, and there it is, sitting just under crude protein and crude fibre: crude ash. It’s a phrase that stops a lot of horse owners in their tracks. Ash? In my horse’s supplement? It sounds like something you’d sweep out of the bottom of a fire grate — and understandably, it’s one of the lines people worry about most.

Here’s the reassuring truth: crude ash is one of the most misunderstood numbers on any feed label, and once you know what it actually measures, it stops being alarming and starts being genuinely useful.

What crude ash actually is

Crude ash is simply the total mineral content of a feed or supplement. Nothing more sinister than that.

The name comes from how it’s measured. In a laboratory, a sample is placed in a furnace and heated to around 550°C until everything that can burn has burned away. The proteins, fats, fibre, sugars and vitamins — all the organic material — go off as gas and smoke. What’s left behind, the incombustible residue, is weighed. That residue is the minerals: calcium, phosphorus, magnesium, sodium, potassium, zinc, copper, iron and the rest. Because it’s literally what remains after burning, it was named “ash”. It does not mean ash has been added to the product — nothing has.

So when a label says, for example, crude ash 8%, it’s telling you that 8% of that product, by weight, is minerals. That’s the whole story.

Why it’s on the label at all

In Great Britain, crude ash isn’t optional. Feed law — the retained version of Regulation (EC) No 767/2009 — requires manufacturers to declare a short list of “analytical constituents” on compound feeds and many supplements. Crude ash sits in that list alongside crude protein, crude fibre and crude oils and fats. So every compliant bag or tub you pick up should carry it. It’s there for a good reason: to give you a consistent, like-for-like way to compare what’s actually in the sack.

What the number can — and can’t — tell you

Here’s the part that matters most, and it’s where the myth creeps in. Crude ash tells you the weight of minerals in a product. It tells you nothing about their quality, the form they come in, or how much of them your horse can actually absorb and use.

That difference is everything, because you can arrive at the same mineral figure in two very different ways. You can bulk a product out with cheap inorganic minerals — the heavy, low-cost oxides and carbonates that add a lot of physical weight to the tub. That pushes the ash figure up, yet a good deal of it can pass straight through the horse. Or you can deliver minerals in a smaller amount of a more bioavailable form, where less physical material does more work. That keeps the ash figure low — not because the product is short on mineral support, but because it isn’t padded out with weight the horse can’t use.

So a high ash number isn’t automatically a sign of generosity, and a low one isn’t automatically a shortfall. The figure on its own simply can’t tell you which is which. You have to look at how the minerals are delivered.

Reading it the Hi Form way

This is exactly why our ash content sits low. We build our formulas on mineral tissue salts — highly bioavailable microdoses of the body’s essential minerals — rather than bulking the tub out with cheap inorganic minerals. The mineral support stays high, and the quality stays high, but the physical mineral mass, and with it the crude ash, stays low.

Put simply: we’re not asking you to pay to ship dead weight, and we’re not asking your horse to process it either. It’s high-quality mineral support, delivered in a form the body can use, without the bulk — the same thinking that runs through everything we make. The benefit, and none of the filler.

When to raise an eyebrow

There is a version of high ash that’s worth questioning — and it’s the one the myth is really pointing at. If a product shows a high ash figure but the label gives you no mineral detail to explain it, that’s your cue to ask what’s making up the number. In cheaper feeds it can occasionally reflect inexpensive mineral bulking; in low-grade, forage-based products it can even reflect soil and grit that came in with poorly cleaned raw materials.

That’s the whole argument for transparency in a single line: a good label doesn’t just tell you the ash figure — it shows you what’s inside it.

The takeaway

Crude ash isn’t a number to fear, and it isn’t a scoreboard either. It measures the weight of minerals in a product — not their quality, and not how well your horse can use them. Read it alongside the bigger picture: what the product is for, what form its minerals take, and how open the brand is about what’s inside.

That’s the test we hold ourselves to. It’s the same question behind everything we make: would we feed this to a horse we loved? If the answer’s yes, we’re happy to show you every last gram of why.

Hi Form Equine UK — the science of natural health. No filler, no fluff, no shortcuts.