Protein is the body's building block for muscle, coat and hooves. A horse can easily look round and still lack protein, so it's important to know the requirement and the signs of deficiency.
Your horse needs approx. 1.5 g crude protein per kg of body weight per day, i.e. approx. 150 g per 100 kg. A 500 kg horse needs approx. 750 g crude protein daily.
If the forage is to cover it alone, it needs approx. 10 % crude protein in the dry matter. If your analysis is lower, supplement with soya bean meal or alfalfa.
Requirement and supplementation per day
Your horse's weight
Total crude protein
Soya bean meal at 6 % in the forage
300 kg
450 g
375‑390 g
400 kg
600 g
500‑520 g
500 kg
750 g
625‑650 g
600 kg
900 g
750‑780 g
The soya bean meal column is the example where the forage has only 6 % crude protein in dry matter.
Signs of protein deficiency
Big belly, but flat or weak muscles over the back, hindquarters and shoulders
Doesn't build muscle, even though you're working it
Dull coat with no shine
Brittle or crumbling hooves that grow slowly or crack
Less energy and stamina in training
Young horses that are slow to develop in body and muscle
Go by the signs above, two or more point to too little protein
Top up with soya bean meal or lucerne, protein can always be added afterwards
Track the muscles over time, coat and hooves change the slowest
Remember that a horse can look round in the belly and still lack protein
Want to know more?
What protein does in the body
Protein is the building block for muscle, tissue, coat and hooves, and it is essential for your horse's health and metabolism. If your horse doesn't get enough, it can look round over the belly and still lack muscle elsewhere on the body.
That's why body condition alone is a poor measure of whether the protein is right. Look at the topline, the hindquarters and the shoulders instead.
When the forage isn't enough
If the forage is to stand alone, it should contain approx. 10 % crude protein in dry matter. Many batches are lower, and the difference then has to come from the feed bucket.
Example: if your forage contains 6% crude protein, add approx. 125‑130 g soya bean meal per 100 kg of horse per day. For a 500 kg horse, that's 625‑650 g daily.
Too much sugar in your forage can't be corrected afterwards. You can always add protein, which is why protein is rarely the limiting factor once you know the figure.
Good sources of extra protein
Soya bean meal and alfalfa are the two sources we recommend. Soya bean meal is the most concentrated, which makes it the easiest to dose precisely from an analysis figure. Alfalfa adds both protein and structure to the diet.
Choose your source based on how big the gap is: the further your forage is from the 10%, the more concentrated the supplement needs to be.
Selected articles from the knowledge bank
Protein sources for horses, what's the difference? · The amino acids in horse feed sources, with a focus on lysine, methionine and taurine · Poor-quality hooves, why biotin is rarely enough · Is protein really harmful to older horses, or have we misunderstood something?
