What the Heck Is forage based fibre feed?

https://natural-horse-feed327.urbanvellum.com/posts/horse-feed-for-chaff-and-cubes-a-practical-overview

Gentle horse feed for sensitive stomachs, designed to support gut comfort, intestinal health and easy nutrient absorption. A low-starch fibre-rich formula with natural ingredients to help maintain settled digestion and overall health.