What the Heck Is low starch competition feed?

https://balanced-horse-feed827.cavandoragh.org/what-horse-feed-should-a-horse-eat-after-a-race

Gentle horse feed for sensitive stomachs, designed to support comfortable digestion, hind gut health and efficient nutrient uptake. A low-starch high-fibre formula with naturally sourced ingredients to help maintain settled digestion and overall wellbeing