Is it true hay should cure for a certain amount of time prior to it being fed to horses? Or is it safe to feed immediately after baling?
It is a common myth that hay must cure for weeks or even months before being fed to horses. Generally, hay dried correctly prior to baling will be safe to feed right away, though its suitability depends on several different factors.
The Risks of High-Moisture Content Hay
Producing hay is both a science and an art. Because weather has a significant impact on farmers’ harvesting timelines, moisture content in hay can vary drastically. When farmers harvest hay, they cut the plants, leave them to dry in the field, and then rake them to ensure the hay dries evenly. Depending on the environmental conditions, this process can take a few days. Typically, hay is ready to be baled when it reaches about 15-22% moisture. Farmers can bale and store hay on slightly windy, less-humid afternoons after dew has evaporated to help avoid higher moisture levels.
Hay baled with more than 22% moisture often ferments, a process horse owners refer to as “sweating.” How long a hay bale sweats depends on moisture content, grass types, and bale density. These wet, incompletely cured bales are where we get the curing time myth.
Baling hay with moisture content over 15% can be unsafe for horses and barns, even after weeks of curing. Excess moisture can promote harmful mold growth, impacting horses’ respiratory health. It can also foster heat-causing bacterial growth, compromising the hay’s nutritional value and creating conditions for further bacteria that elevate internal bale temperatures to combustion risk. If you open a bale and feel heat, never feed it to your horses.?
Purchasing Safe Hay
When purchasing hay for your horse ask the producer questions about the moisture and harvesting conditions. Safety for your horse should be the priority when choosing forage, along with nutritional suitability.
Always allow for a transition period when feeding your horse a new hay. Some of the concern about new hay stems from gastrointestinal upset caused by rapidly changing fiber sources in the horse’s diet. To reduce the risk of GI upset, begin introducing the new hay at 25% of your horse’s daily amount and slowly increase over seven to 14 days.
Take-Home Message
To promote gastrointestinal health in your horses and reduce safety issues, purchase hay that was dried correctly in the field because it will be safe to feed right away and less likely to develop mold. Make any hay changes slowly over seven to 14 days to reduce your horse’s risk of GI upset.
