What breaks down the fiber in a horse?

Horses are herbivores, meaning they primarily eat plants. They have a digestive system specifically designed to break down the tough fibers found in plants, but they can't do it alone! Here's how it works:

1. The Horse's Role:

* Chewing: Horses chew their food thoroughly, breaking down the large pieces into smaller particles. This is the first step in mechanical digestion.

* Saliva: Horses produce a lot of saliva which contains enzymes that start breaking down the starch in their food.

* Stomach: The stomach churns and mixes the food, adding more digestive juices.

* Small Intestine: This is where most nutrient absorption happens. Enzymes from the pancreas and bile from the liver help break down fats and proteins.

2. The Microbes' Role:

* Cecum: The cecum is a large pouch at the beginning of the large intestine where the magic happens! This is where billions of helpful bacteria live and work their magic. These microbes ferment the tough fibers (cellulose and hemicellulose) that the horse's digestive system can't break down. They produce volatile fatty acids (VFAs) which are then absorbed by the horse as an energy source.

* Large Intestine: This is where water absorption occurs. The microbes continue to work here, extracting remaining nutrients from the food.

So, it's a team effort:

* The horse: Chews, mixes, and provides the initial digestive enzymes.

* The microbes: Ferment the fibers and produce energy for the horse.

Important Note: Horses are hindgut fermenters, meaning the majority of their fiber digestion takes place in the hindgut (cecum and large intestine). This is different from ruminants like cows, which have a four-chambered stomach where the bulk of fermentation occurs.