There are undoubtedly pros and cons to steaming or soaking hay and the first step is establishing what you are hoping to achieve. If you are looking to improve the hygienic quality of hay then both options are open to you but if you are looking to remove water soluble carbohydrates (WSC) then soaking is really the only option as steaming doesn’t have a significant effect on WSC content.
Steaming hay involves placing hay within a chamber where steam will pass through it. In general, commercially available steamers are deemed as safe, with repeatable, effective results. Hay is usually steamed for about an hour, reaching temperatures of at least 80°C for 10 minutes within this period before it is removed.
A potential benefit of using steamed hay is the fact that steamers are scientifically proven to not only reduce, but eliminate 99% of dust, bacteria and various fungus and moulds. As these are all commonly found in hay and can cause some serious health issues for your horse, steaming can prove to be life changing for them.
Steaming hay, however, is not a fool proof process. Some individuals may try and create homemade steamers, which can cause some issues. Homemade steamers are unlikely to reach the ideal temperature necessary to have a positive impact on hay. This can lead to bacterial growth, which can damage your horse’s health.
To soak hay, it must be completely submerged and fed to your horse very quickly afterwards for the hygienic benefits to remain. Compared to steaming, soaking hay is one of other horse food that can lead to many valuable nutrients also being lost and it is now suggested that it may be necessary to feed more hay that has been soaked to ensure sufficient fibre is consumed by the horse to maintain normal gut function. Soaked hay is generally not as palatable as steamed hay and it can be heavier to lift out of the soaking vessel so not feasible for everyone to manage. There is also the added challenge of frozen taps and water in the winter months and in the summer, hotter conditions can mean that soaked hay starts to ferment and so it can’t be soaked for such long periods.
Additionally, following soaking, a large amount of contaminated water will need to be disposed of carefully and if produced on a large scale such as on a large livery yard, it shouldn’t be tipped into drains as it is classed as effluent.
Soaking to reduce the sugar content
When hay is soaked, some of the WSC (water-soluble carbohydrates) can be lost as a result. The level of WSC removed from the hay will depend on the ratio of hay to water, temperature and period of time it is soaked for. The general rule of thumb is that the more water to hay there is and the warmer the water is, the more sugar will be removed. A general recommendation is up to 10-12 hours soak time in cool conditions and 2-3 in hot conditions to avoid fermentation but never rely on soaking to make a high sugar hay safe – always try to source a low sugar forage in the first place!