8 Steps to Prevent Colic as Horses Transition to Hay

3 Make changes gradually. This will give the bacterial flora in the hindgut a chance to become accustomed to the forage source. 
4 Offer a prebiotic. A prebiotic contains fermentation products rather than live microbes which feed the existing population in the hindgut. This makes forage digestion more efficient.
5 Provide clean tepid water. Icy cold water is often rejected leading to decreased fluid in the digestive tract. It is best to heat the water supply to approximately 10 degrees C 50 degrees F to ensure enough consumption. 

6 Dont forget the salt. Salt is needed year round. A full sized horse requires approximately 2 tablespoons one ounce or 28 grams of table salt per day divided between meals to encourage him to drinking to prevent impactions. Salt blocks are often ignored because of the discomfort that constant licking creates. Consider offering table salt free choice by pouring some in a nearby bucket. 
7 Have your horses teeth floated annually. Poor dental health leads to partially chewed hay which can cause impactions throughout the digestive tract.
8 If possible have your hay analyzed. If you have two months supply or more it is worth having your hay analyzed for its sugar and starch content as well as the protein minerals and selenium levels.
In summary continuous grazing without gaps will keep the intestinal motility normal prevent acid buildup and protect the vital foragedigesting hindgut microbes. Reduced water consumption due to increased dry matter in hay andor cold water temperature is one of the main causes of colic in the winter. To prevent digestive health problems be consistently consistent with your horses care and feeding make slow transitions and allow your horse to be a horse just as much throughout the cold months.