Wed, 01 Apr 2026 07:56:02 -0400WeeblyThu, 28 Oct 2021 13:21:45 GMThttps://www.achaina.com/hot-topics/feed-changesChanges to a horse's diet need to be made slowly to avoid colic.

A large amount of digestion in the hind gut is performed by bacteria, also know as microflora. 

Different bacteria digest different things.  The horse's gut has a balance of bacteria (known as the microbiome) that has adapted to digest the proportionate amounts of fiber, sugar, starch, and protein that your horse eats daily.

If any changes are made to what is being fed, it disrupts the microbiome and the bacteria need to repopulate and adjust to the new ratios.  Even if you are just changing from one hay cutting to another, the bacteria need time to adjust because the fiber, sugar, starch, and protein levels will be different.

A good rule of thumb for feed changes is to make a 25% change every 3-5 days (out with the old, and in with the new), so the bacteria population has time to adjust and the horse can digest properly.

New feeds being added should be added in small quantities and increased gradually every 3-5 days.

From The Horse's article Dealing with Equine Colic - 33 Do's and Don'ts: 
“The most common association with colic is a change in feed or hay batch within the prior two weeks", says Dr. Daniel Keenan. "When switching to a new food source, try to do so gradually over at least 10 days."]]>