Does Bermudagrass Hay Cause Colic in Horses?

This is one of the long debated topics among horse owners and equine veterinarians in the Southeast for the last several years. The problem is that after years of debate, as well as a few research trials that have attempted to answer this question, we still do not have a definitive answer to this age-old question. Despite not having a clear-cut answer, we do know a few things about Bermuda hay and impaction colics.

·        The type of colic associated with bermudagrass is an ileocecal colic, which is difficult to treat but not very commonly seen (as far as colics go).

·        Water intake (or more specifically lack thereof) is directly related to this type of colic. So for horses that have restricted access to water, or are slow to drink due to weather conditions, this compounds the chance of colic greatly.

·        Bermudagrass hay, no matter how high the quality, is not as easily digestible as Timothy or good Alfalfa.

·        Horses that are suddenly switched to a mature Bermuda hay from green forage or a timothy-type hay are much more prone to colic-type problems than ones that are gradually introduced.

Finally, the biggest factor that is associated with Bermuda colic is the level of maturity of the grass at harvest. While other factors such as the presence of mold and weeds will affect the quality of hay, the maturity level tends to be the major deciding factor with associated colics. The more mature a bermudagrass plant is at harvest, the lower the digestibility the resulting hay will have. To try to put a value on this, you will need a full analysis of the hay in question. The ADF value (acid detergent fiber) measures the digestibility of the hay. Hays with values  below 35% are considered very digestible, while hays with ADF values above 35% are going to be less digestible, and more prone to cause problems.

 So what does this mean to the average horse owner who is feeding Bermuda hay? In a nutshell, if your horse(s) have been on Bermuda hay for more than a few weeks and has never experienced any type of impaction colic, you should at least feel that your horse can probably handle Bermuda hay barring an unforeseen issue. On the other hand, if you have a horse that has had some colic problems in the past, and is not a big drinker, you probably would do well to keep a close watch on them and pay attention to your hay quality. Below is a guideline for things to watch for;

·        Make sure the hay you are buying is relatively “young” hay, or is  “horse” quality A hay analysis can help you determine this (measuring the ADF values mentioned above), but so can an experienced eye when the time comes to purchase your hay for the winter.

·        Use common sense and proper management when introducing a newly purchased or boarded horse onto Bermuda hay. Don’t allow horses to gorge themselves on Bermuda hay the first few times they are fed it.

·        Make sure they are getting proper water intake.

·        Finally, if you know a particular horse is prone to colic, keeping that horse on a timothy or alfalfa mixture may be cheaper in the long run than a colic surgery.

So while no clear answers are to be had for the question of does Bermuda hay cause colics, it is clear than some horse will be easier to manage on Bermuda than others. 

Written by Randy Wood, County Extension Director and Livestock Agent, Scotland County

(with excerpts from Dr. Bob Mowrey, NCSU Animal Science)