Dieting for Disposition

Q: Is it possible to feed a horse with the goal of improving his behavior?


Shannon, via e-mail

A: The answer to this question obviously depends on the horse's current diet and work, as well as what behavior you want to improve. But, for sure, the short and general answer is yes. Diet and feeding schedule, exercise, and style of human handling are likely the three most important factors in horses' behavioral health. When evaluating a specific behavior problem or when advising clients on maintaining their horses' behavioral and physical health, equine behavior specialists put a lot of thought into diet--not only what owners are feeding, but also the feeding schedule. Diet and feeding schedule are particularly important when it comes the most common vices: cribbing and other stereotypies, wood chewing, hyperactivity, or other problems associated with a "hot temperament" or tendency for anxious "meltdowns."

Some of the current recommendations concerning effects of diet and feeding schedule on behavior are based on research, but most are based on experience and anecdotal evidence. This is one topic that could certainly benefit from more research, using well-designed studies in which the behavior evaluations are done by a researcher who is blinded to each horse's diet and feeding schedule.

Providing your horse free access to forage (grass or hay) is important for both behavior and health. The horse's digestive system has evolved to accommodate near-continuous ingestion of calorie-sparse roughage. In natural settings, which are in my opinion the gold standard of health and normal behavior, the stomach is probably never empty nor full. Gastric ulcers and their associated problematic behavior changes in these scenarios are probably quite rare.

In general, horses that can be maintained in reasonably good condition on mostly grass and grass hay seem to have the fewest behavior problems and also seem to have the most relaxed and easiest dispositions. This type of diet is closest to that for which the equine digestive system evolved to handle. Grazing species foraging under natural environmental conditions move as they forage continuously. In contrast, horses in stalls or paddocks with hay bunks are likely stationary while feeding. For horses fed in stalls, divide hay into small amounts placed at multiple locations around a stall. Most horses when eating will move from pile to pile in a style of "take a couple bites, take a couple steps," that resembles natural movement during grazing. It may take a few days for this "stall grazing" behavior to emerge, but for most horses it does. It is my impression from watching 24/7 videos of horses in stalls fed in one place versus being fed so that they "stall graze" that their behavior pattern appears more normal and relaxed. They take considerably more footsteps per 24 hours when "stall grazing," and they do so in a normally relaxed manner similar to horses grazing naturally.

For horses in heavy training or work that require more energy than can be provided with forage alone, feeding calories from oils (fat) rather than carbohydrates has been shown to result in fewer undesirable behavioral and physical health effects. Many of the currently marketed feed formulations have higher percentages of fat than the traditional sweet feeds. These higher fat formulations are recommended for preventing and alleviating behavior problems such as hyperactivity, stereotypies, "hot" or "anxious" temperament, and so forth.

Food urgency and food-related aggression are particular behavior problems that result from feeding infrequent highly palatable, calorie-dense grain meals. A fair percentage of horses will become food urgent to the point of becoming anxious, hyperactive, and/or aggressive at grain feeding time or whenever they anticipate a grain meal. They may develop a stereotypy such as weaving, tongue lollying, or pawing associated with feeding times. They may guard their feed tub or that area of the stall and paddock, or even the person who feeds them. Food-urgent horses in turnout can be dangerously aggressive toward pasturemates. When in a stall they can be aggressive toward caretakers at feeding time, sometimes lunging toward the feed tub or feed scoop, or even turning butt and double barrel kicking to knock the feed bucket out of your hands. For such horses, an all-forage diet usually eliminates the problem.

Finally, nutritional supplements, often marketed specifically for behavioral health, are a very interesting yet frustrating topic for horse owners and managers as well as for equine nutrition and behavior specialists. As is the case for nutritional supplements for humans, so many are available, but for most there is little to none, or widely conflicting, research evidence of their efficacy. In many instances, while it is assumed that feed supplements are safe, there often is no research addressing their safety.

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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