Recent studies in England have addressed problems related to horse health and the feeding of hay. Many veterinarians recommend soaking hay fed to horses that are prone to laminitis. In addition, studies have been done to research the benefits of steaming hay to rid it of bacteria, fungi and yeast to improve the hygienic quality of the hay especially when it is fed to performance horses.
Hay testing for water soluble content
Studies show that soaking and steaming hay has some benefits for horse health.
In one study, five bales of English rye grass mix meadow small baled hay were steamed in the Haygain hay steamer using its unique method to introduce steam through a manifold system for 50 minutes.
Microbiology test results showed that steaming in this way was very effective at reducing total viable count of bacteria, 99.08% and 98.84%, respectively and 100% reduction in fungi and yeast of the hay. This drastic improvement in the hygiene quality of whole bales of hay makes it a safe and suitable fodder for all types of horses.
In the study, led by Annette Longland, BSc, PhD, DIC, of Equine and Livestock Nutrition Services in Wales, U.K., a group of researchers set out to test the effects of soaking on the water soluble protein (WSC) and crude protein (CP), to see how much protein was leached during hay soaking of nine different hays from England and Wales.
High WSC levels markedly affect blood-insulin responses in horses and often cause an exaggerated response in laminitic or IR horses. Exaggerated insulin responses can lead to potentially life-threatening bouts of laminitis.
Grasses and hays high in water-soluble carbohydrates (WSC) can spell disaster for horses with laminitis or insulin resistance (IR). Some veterinarians and nutritionists suggest soaking hay to reduce the amount of WSC in the hay (because water-soluble means these simple sugars dissolve in water), but how much WSC content does soaking actually reduce? According to one team of researchers, it varies depending on how long the hay is submerged.
The research team completely submerged two kilograms of the mixed species meadow or ryegrass hays either compacted in the flakes or shaken loose of the flake in large plastic tubs filled with 24 liters of 8°C (46°F) tap water. Hays were soaked for 20-minute, 40-minute, three-hour, and 16-hour periods. The researchers then dried the hays in an oven before analyzing them chemically.
As it turns out, soaking hay in water does reduce the WSC, which are comprised mostly of fructans and the simple sugars glucose, fructose, and sucrose, but "there was great variation between individual hays in the amounts of WSC leached," the team reported.
In short, If your horse has a metabolic condition that puts him at risk for laminitis if he consumes too much carbohydrate, the best practice is to buy the lowest-carbohydrate hay you can find and soak it as long as possible or practical to remove some carbohydrates.
Soaking removes some protein as well as carbohydrate, but because most hays don’t contain a high level of protein, this may not be very important to the horse’s total protein consumption. In this study, loss of protein was not significant regardless of the length of time hay was soaked.
Steaming hay in the Haygain hay steamer drastically improved the hygiene quality of whole bales of hay. The microbial contamination was reduced to zero for fungi and yeasts and by 98.84% for bacteria. Minimizing exposure to these respirable particles is hugely beneficial to the health of the horse and in particular the respiratory system. Pathogenic challenge to both the respiratory and digestive systems is therefore all but eliminated making the steamed hay an excellent feed for all performance horses.
For owners of laminitic horses, Longland recommends getting the hay tested for water soluble content, preferably after soaking it, so you know exactly how much your hay contains. Otherwise, if hay is tested before it is soaked, use soaking as an added safeguard if necessary.
You may want to read Special Dietary Needs of Horses for more information.