For digested material to exit the horse's cecum, it has to actually defy gravity! To process food, the cecum contracts to push the contents out the top. To do this critical digestive function, forage needs to be flowing through the digestive system at all times.
Picture a full toothpaste tube that is open. If you squeeze the bottom of the tube, toothpaste will come out the top because it is full. Picture a half empty toothpaste tube, with the paste at the bottom. Squeeze the tube and no toothpaste comes out the top because there isn't enough inside.
Without enough food matter to “fill the tube” (cecum), sand, dirt and undigested material can remain at the bottom, leading to colic. Avoiding this is simple: Feed your horse a continuous supply of forage--all day and all night. This will keep the cecum full enough to push the contents up to the exit and send them along the digestive/elimination chain.
Worried about weight gain? No need. Feed a low calorie, low NSC hay, free-choice, and your horse will let you know how much he needs to maintain his weight.
Juliet M. Getty, PhD, is an independent equine nutritionist with a wide U.S. and international following. Her research-based approach optimizes equine health by aligning physiology and instincts with correct feeding and nutrition practices. Find a world of useful information for the horseperson at www.GettyEquineNutrition.com. Sign up for Getty’s informative, free e-newsletter, Forage for Thought; browse her library of reference articles; search her nutrition forum; and purchase recordings of her educational teleseminars. Reach Dr. Getty directly at firstname.lastname@example.org. She is available for private consultations and speaking engagements.