What the Heck Is low-starch horse feed?

https://horse-feed-formula007.quillnesty.com/posts/what-horse-feed-is-most-suitable-for-cob-horses

Gentle horse feed for sensitive stomachs, designed to support comfortable digestion, intestinal health and better nutrient absorption. A low sugar high-fibre formula with naturally sourced ingredients to help maintain calm digestion and overall wellbeing.