Q: I was reading an online forum and they were discussing hay. A couple people posted how a horse needs stemmy, coarse hay to keep from colicing. They said soft, grassy hay will make them colic. I always thought soft, grassy hay was good for horses. What should I do?
A: There are numerous things that cause colic, but good quality hay is usually not one of them. Both stemmy and soft hays can be considered good quality; given both are free of dust, weeds, and mold, and should not affect the incidence of colic. Stemmy hay is usually more mature with less energy and nutrients and can be a good choice for adult, idle horses, or horses that need to lose weight. Softer hay is usually more immature and leafy with higher energy and nutrients levels. This hay is usually ideal for horses with a greater demand for energy like working, reproducing, and young, growing horses. In fact, a diet high in forage usually reduces the incidence of colic compared to diets high in grains.
Low quality hay that is dusty or moldy can increase the chance of colic. Overly coarse hay has been linked to impaction colics, and soft hay might cause colic if horses overindulge or a shift to a softer, more digestible hay is made abruptly. When making any feeding changes, the changes must be made slowly, this includes changing forage types.
If you are concerned about the incidence of colic, speak to your veterinarian and ensure your horse is in good health. Causes of colic can be unexplainable, but a diet high in consistent, quality forage should pose a limited risk of colic.
By Krishona Martinson, PhD, and Julie Wilson, DVM, University of Minnesota