The How and Why of Soaking Hay

 to Soak Horse Hay?

For sheer convenience, it’s hard to beat soaking hay in a hay net submerged in a large garbage can or plastic tote. Remember, water volume is important. Stuffing several hay nets into one large container with minimal water will not be as effective at removing WSC as one hay net in abundant water. Choose a container that is easy to keep clean and can be stored in a clean place when not in use. After one hour of soaking, the submerged hay can be pulled out and the water disposed of on the manure pile or down a drain. If you pour it out on the ground it can attract flies and wasps in warm weather, or create an icy patch in winter. The hay can be further rinsed under the tap to remove any residual soaking water. Choose a hay net with smaller holes to avoid losing a lot of leaf in the water. As much as possible, feed the soaked hay immediately, and feed in a cool, well-ventilated place in the summer.

What are the Advantages of Steaming Hay?

Steaming hay in a commercial hay steamer is popular in the United Kingdom, and is gaining in popularity in North America. One significant advantage of feeding steamed hay instead of dry hay is the reduction in dust and mold spores that may be present. Horse owners know well to avoid feeding musty or moldy hay, but it does happen sometimes despite our best efforts. Steaming hay for 50 to 90 minutes in a commercial steamer will reduce the particulate matter in the hay, making it easier for some horses to eat. It will also render inactive many of the mold spores and possibly mycotoxins that may be present in a hay that is not the best. 

Is Steaming a Replacement for Soaking Hay?

Steaming hay is very effective at increasing palatability of a dry hay and it does reduce the WSC of hay somewhat, but it is not as effective as soaking for removing sugars from a hay. The good news is that steaming removes far less of the other nutrients when compared with prolonged soaking.

The effects of steaming on the availability of some of the carbohydrates sources are not yet fully understood. From a nutritional perspective, it’s logical to assume that “cooking” by steaming the hay may well be making some of the complex sugars that are typically utilized in the hind gut of the horse more digestible and therefore more likely to be utilized in the foregut. This could potentially increase blood glucose and consequently stimulate an insulin response, something we want to avoid in a metabolic horse. Until more research is completed it may well be advisable to continue to soak the hay of your IR, EMS, or PPID horse, or any horse with sugar sensitivities. 

Just like soaked hay, steamed hay must be fed quickly before it spoils, especially in hot weather.

Soaking hay for the metabolic or overweight horse can be a helpful management tool, especially if faced with a barn full of hay that isn’t suitable for all horses in the stable. But if not done correctly, it can also be a recipe for a messy yard and a horse off its feed. If you decide that soaking hay makes sense for your horse, keep in mind that soaking longer is not always better, hot water isn’t necessary, more water increases the dilution gradient for ALL nutrients, water and containers must be clean, and the spent water should be discarded in areas horses can’t access.