Scientific and Equine Consultant

Concentration, Content & Percentage on Equine Feed & Supplement Labels – How to understand what you are really getting!

Concentration, Content & Percentage on Equine Feed & Supplement Labels – How to understand what you are really getting!

Dr David Marlin

Supplements for your horse should not necessarily be cheap! If they are cheap, then they probably don’t contain:

  1. very many ingredients

  2. high levels of ingredients

  3. high quality ingredients

  4. expensive ingredients

In order to make their supplement look good compared with others, some companies will choose to market on PERCENTAGE or CONCENTRATION of ingredients rather than on CONTENT. This make their product look very good, especially if they are one of the companies that also markets strongly on “NO FILLERS, CARRIERS or BULKING AGENTS”. As an aside, the latter are often required for technical reasons such as improving shelf-life, ensuring even distribution of the ingredients and ease of dosing (e.g. being able to use a 25ml scoop as opposed to having to give you a 19.5ml scoop or some other strange size).

Here is a clear explanation of what these terms mean and why PERCENTAGE can be very misleading. PERCENTAGE is the amount of an ingredient in a supplement in grams per gram x 100 (or it could be mg per mg or kg per kg). So if there is 20g of an ingredient in 100g of supplement that is 20%. It’s also the same as CONCENTRATION in this case. You will also sometimes see on labels the amount of ingredient in a supplement expressed as g/kg or mg/kg or IU/kg – this is a CONCENTRATION (but could be converted to a %).

In the case of pure glucosamine for example in a supplement with nothing else, then the PERCENTAGE or CONCENTRATION will be 100%. This dose NOT tell you how much your horse will get of the active ingredient. For that you need to know the FEEDING RATE (amount of supplement fed per day). So as an example, if the label on a joint supplement says The FEEDING RATE is 50g per day and the glucosamine is listed on the label as 100g per kg:

*The CONCENTRATION of glucosamine in the product is 100g/kg or 10g/100g (these are the same)

*The PERCENTAGE of glucosamine in the product is 10%

*The CONTENT of glucosamine in a 50g dose is 5g (the amount of glucosamine the horse gets per day)

So on paper a company might claim their supplement has “NO FILLERS” and provides 100% glucosamine (or a higher PERCENTAGE of glucosamine than another) but when you take the FEEDING RATE into account it may deliver less active ingredient than one in which the glucosamine PERCENTAGE is only 50%.


Glucosamine PERCENTAGE 100%
Glucosamine CONCENTRATION 1000g/kg
FEEDING RATE 10g/day/500kg
Glucosamine CONTENT (amount of glucosamine horse gets) 10g

Glucosamine PERCENTAGE 20%
Glucosamine CONCENTRATION 200g/kg
FEEDING RATE 100g/day/500kg
Glucosamine CONTENT (amount of glucosamine horse gets)  20g

So supplement X is 100% glucosamine but only delivers 10g glucosamine per day (10g = the CONTENT) whilst supplement Y is only 20% it delivers twice as much glucosamine per day – 20g (20g = the CONTENT). And this is why PERCENTAGE is meaningless and misleading.

Now, if we compare two different joint supplements, A & B (these are two actually on the market), we can see that on the upper PERCENTAGE graph supplement A looks to be way ahead except that it does not contain Vitamin C or Omega 3. However, if we now look at the lower CONTENT graph, we can see that the picture is very different. A is still slightly higher in glucosamine, lower in MSM, slightly lower in chondroitin sulphate and much lower in HA.


BOTTOM LINE – PERCENTAGE or CONCENTRATION on their own are meaningless and misleading! CONTENT is the most important.

Date: October 21, 2016