Protein for the horse: Soybean meal versus Horselux Green Protein – see the significant difference

Your horse needs protein for muscles, hooves, fur, immune system and hormones .
But it's not enough that the bag says a high percentage - what matters is how much of the protein the horse can actually absorb and utilize .

We have calculated two popular protein sources – and the difference is significant:

This is how much your horse needs to absorb 150 g of usable protein per day:

Soybean meal (45% crude protein, approx. 90% absorbable)

• 370 g per day
• Price per day: approx. 3.13 kr
• Price per 100 g of absorbed protein: approx. 2.09 kr
• Sugar: approx. 7% – Starch: approx. 3–4%
• Documentation: Farley et al., 1995 – “soy protein is almost completely digestible in horses”.

Horselux Green Protein (53% crude protein, assumed 55–60% absorbable)

• 472–515 g per day
• Price per day: approx. 37.7–41.1 kr
• Price per 100 g of absorbed protein: approx. 25–27 kr
• Sugar: approx. 1% – Starch: 0%
• Documentation: Product data from Horselux. Absorbability calculated from typical values ​​for grass protein (Saastamoinen et al., 2021; Sciencedirect, 2021). No published data for this specific product.

What do the numbers show?

• Soybean meal provides the same amount of usable protein for less than 1/10 of the price.
• Horselux Green Protein is much more expensive – and its absorbability has not been documented.
• If you want the most protein for your money – and well-documented effects – soy meal is the obvious choice.

Calculations: August 2025 – Soybean meal: DKK 169/20 kg (45% crude protein, approx. 90% absorbable).
Horselux Green Protein: 799 DKK/10 kg (53% crude protein, assumed 55–60% absorbable).

Sources:
Farley et al. (1995): Protein digestion in horses.
Saastamoinen et al. (2021): Protein absorption from roughage.
Sciencedirect (2021): Pre-cecal digestibility of grass proteins.