What the Heck Is low starch diet feed?

https://equine-feed241.publishlane.com/posts/horse-feed-for-slow-release-energy-what-to-choose-and-why

Gentle horse feed for sensitive stomachs, designed to support gut comfort, hindgut health and better nutrient absorption. A low-starch fibre-rich formula with naturally sourced ingredients to help maintain steady digestion and general wellbeing.