The equine digestive system is designed to process feed for most of the day. With modern management practices, horses are typically housed in stables and fed regulated meals a few times a day. Long intervals between meals can lead to digestive issues and behavioral problems. For this reason, methods that shorten feeding intervals and extend eating time can be beneficial for both digestive health and for occupying horses during time spent indoors.
From a digestive perspective, frequent intake of small amounts of feed is most natural for horses. Various slow-feeding options can be used to reduce eating speed and shorten fasting periods. One study in horses showed that the time spent eating was up to 61% longer when hay was fed from a hay net compared to free feeding from the ground.
In another study*, which examined the benefits of slow feeding, researchers hypothesized that hay nets with smaller holes would increase chewing frequency compared to feeding from the ground. Chewing stimulates saliva production, which contains bicarbonate—a compound that buffers stomach acidity. More chewing means more bicarbonate.
The horse’s digestive system produces gastric acid continuously, but saliva is only produced during chewing. Therefore, continuous or prolonged chewing may help reduce the risk of gastric ulcers by increasing bicarbonate production via saliva.
To test the hypothesis that hay nets increase chewing and alter chewing dynamics, researchers fitted eight horses with “chew halters.” These devices recorded individual chews using a pressure sensor located in the noseband. The horses were stabled and fed hay at 1.5% of body weight twice daily at 8:00 a.m. and 4:00 p.m. The researchers recorded the number of chews per kilogram of hay, chewing duration (total chewing time per day), and the proportion of chews occurring during the first 120 and 240 minutes of feeding.
The horses were fed using hay nets with large holes, hay nets with small holes, hay nets with a single bottom hole, and unrestricted feeding. Contrary to the researchers’ hypothesis, hay nets did not increase chewing frequency. However, horses fed from small-hole hay nets chewed for a longer duration than horses fed from the floor. In addition, during the first 240 minutes of feeding, horses fed from small-hole nets performed fewer chews compared to those fed from hay nets with a single bottom hole.
This study demonstrates that slow-feeding options do not increase the number of chews per given amount of hay, but small-hole hay nets do extend the total time horses spend chewing. The study also found that horses consumed a greater quantity of hay from nets with a single bottom hole, indicating that not all slow-feeding solutions are equivalent and should be evaluated carefully.
In addition to hay feeding practices, the sensitive squamous epithelial region of the stomach can be protected from acid damage by feeding products that contain antacids and gastric coating agents. The squamous (upper) portion of the stomach has fewer protective mechanisms against acid compared to the glandular (lower) portion and is therefore more susceptible to acid splash–related ulceration. In addition to stimulating alkaline saliva production, feed intake also helps form a “fiber mat” in the stomach, providing a physical “splash guard” that reduces acid contact with the squamous mucosa.
*Hart, R., A. Bailey, J. Farmer, and K. Dubenstein. 2024. Chewing analysis of horses fed Bermudagrass hay using different slow-feeding styles compared with loose hay. Journal of Equine Veterinary Science: 105133.
