When it comes to feeding horses, many often wonder what to feed first, hay or grain (feed)? This seems like a simple question, with an obvious answer appearing to be hay. Yet, is it feasible, or even practical, for owners to feed their horses hay much earlier than their feed? Better yet, is that even necessary and what does the research say? The results may surprise you.
Should You Feed Your Horse Hay First?
For horses that are on productive pastures and/or given free-choice access to hay, this topic may be irrelevant. A horse’s digestive tract should be receiving a trickle of forage through the day. However, if your horse ends up fasting for an appreciable amount of time (i.e., > 4 hours), then this topic is important!
For horses that are meal-fed, the prevailing wisdom has always been that horses need their forage before introducing feed to their digestive tracts. There have been many reasons postulated why, with the major argument being that hay in the stomach helps slow down the digestion of feed. The logic behind this is that horse feeds are higher in non-structural carbohydrates (sugars/starches) and, when fed in higher amounts, they are not fully digested in the small intestine and can enter the hindgut, which leads to several digestive disorders. For example, our Supporting Your Horse’s Hindgut Health article details how things can go wrong, including:
- Hindgut acidosis
Thus, feeding hay first is logical, if it can slow down digestion of feed and lessen the chance of any sugar and starch from the feed reaching the hindgut.
There are other arguments for feeding horses their hay first. Another is that as the horse chews hay, it produces more saliva, which helps buffer the stomach. Since the horse is meal fed and is hungry, feeding hay first may also slow down how fast the horse eats their feed. All in all, these all appear to be valid reasons and sound advice for feeding hay first.
What Does the Research Say?
When it comes to understanding the arguments on why horses need to be fed hay first, the data is very limited and not too supportive. For example, research studies investigating the passage rates of different feeds in horses’ digestive tracts have found no differences in the amount of time that hay or horse feed spends in the stomach. Nor was the digestion slower in the foregut (stomach and small intestine) when horses were fed hay prior to their feed.
Other studies have shown that, regardless of what the horse chooses to eat first, the act of chewing sends signals to the equine stomach to prepare and quickly move the feed through to the small intestine. Thus, regardless of what is given first, the horse’s small stomach mixes the feedstuff with gastric juices and passes it quickly to the small intestine. So, the theory of feeding hay first to slow down the digestion of horse feed has no scientific support.
What this implies for most horses is that it really does not matter what you feed first. One supporting reason is that because most horse feeds from reputable companies are lower in non-structural carbohydrates (NSC), which reduces the total amount of sugars and starches in the horse’s diet. Second, if you are following sound feeding principles, such as feeding often and feeding smaller meal sizes, most horses will be fine regardless of what is fed first.
Some of our supporting articles on sound feeding practices are worth a review:
- Are You Feeding Your Horse at the Right Times?
- Feed by Weight, Not by Volume.
- Feeding Your Horse Often.
When Feeding Hay First Makes Sense
Of course, with horses, there are always exceptions. When elite athletic horses (i.e., racing thoroughbreds) are fed high NSC feeds due to the massive energy demands placed on them, then feeding hay first makes sense. This is because research data has shown that horses that eat moderate to high NSC meals, prior to eating any hay, produce higher inflammatory markers in their bloodstream. These higher inflammatory markers can have negative health consequences for horses. In later studies, horses fed some hay (~ 2 lb) before a moderate to high NSC meal, had a reduction in these markers. Thus, this is a scenario where horses should be fed some hay before being fed any feed.
Another scenario where feeding some hay prior to feed is best is with horses that “bolt” their feed. This is when a horse eats their feed as fast as they can and is often a behavioral issue. There is some limited data that feeding small amounts of hay prior to being given their feed will slow down consumption. This is important, as it may help reduce the incidence of choke.
Take Home Message
When it comes to meal feeding for most horses, there is no data that supports horse owners having to feed hay before feed. There are no downsides to feeding hay before horse feed, but both can be given at the same time if sound equine feeding principles are being followed.
Again, the exceptions are athletic horses that are being fed moderate to high NSC diets, or those that tend to bolt their feed. In these circumstances, feeding some hay prior to being fed their feed would be beneficial. If you have any questions or concerns about your horses’ diets, please feel free to contact us anytime!
Drogoul, C. et al. (2001). Feeding and microbial disorders in horses: 2: Effect of three hay:grain ratios on digesta passage rate and digestibility in ponies. J. Equine Veternary Science 21:487-491.
Lorenzo-Figueras, M. et al., (2002). Effects of various diets on gastric tone in the proximal portion of the stomach of horses. American J. of Veterinary Research. 63:1275-1278.
Suagee-Bedore, J. et al. (2020). Feeding grass hay before concentrate mitigates the effect of grain-based concentrates on postprandial plasma interleukin-1β. J. Equine Veterinary Science 86:102899.
Van Weyenberg, S. et al. (2006). Passage rates of digesta through the equine gastrointestinal tract: a review. Livestock Science 99:3-12.