Corn has been a staple in the equine diet for a long time now and we tend to accept it as a feed on its own or as an ingredient in a compound feed. It’s easy to understand why corn has been as widely embraced as a feed for horses: it is relatively cheap, high in energy, and highly palatable. In many ways it seems as though it would be a good pick for feeding to your horse, right? Actually, corn isn’t a good pick for horses and here are 5 reasons why.
1. Digestion – Horses haven’t evolved to consume grain. Period. Horses are able to digest a small amount of grain in the small intestine, however, if there is even slightly more than the small intestine can manage, undigested grain can end up making its way into the hindgut. The hindgut is specifically for digesting fiber and when nonfibrous ingredients end up in the hindgut they very quickly disrupt the balance of microbes and the functioning of the gut. Also, microbes in the hindgut will ferment the grain resulting in an increase of volatile fatty acids and lactic acid. This can in turn lead to major digestive upsets including colic and also increases the risk of laminitis. It is worth noting that processed corn is more digestible than whole corn but the same principle applies for all corn, regardless of the processing it has gone through.
2. Starch – Corn is very high in starch, which is known to be a leading factor in raised insulin; a central factor in the development of laminitis and equine metabolic system. It is important for many horses that the starch level in the diet remains low. Shockingly, the glycemic index for corn is 100 – the same as sugar! If you’re trying to keep insulin levels in check and ensure that the starch content of your horse’s diet is low, a good place to start is by checking the ingredients list for maize and corn.
3. High in energy – The digestible energy of corn is very high. The average horse doesn’t require the level of energy provided by corn (if you have a horse in race training, it might be worth considering – for everything else it’s excessive). Many horses today are labeled as “bad,” as having a “poor attitude” or being “naughty.” Often the source of behavioral problems can be found in the feed and excess energy being provided is a key root of that problem. As riders and horse owners, we have a tendency to overestimate how hard our horses are actually being worked and therefore how much energy they need. Corn, with its high level of energy, can be a source of behavioral problems that can be easily alleviated by eliminating it from the diet.
4. Mold and Mycotoxins – Corn is prone to spoiling and molding. Mold that forms then releases mycotoxins, which can be harmful to equine health. Corn added to a compound feed is unlikely to be contaminated with mold as companies will have tested for the presence of molds in each batch before production. However, in order to protect spoilage of the feed later on and to enhance shelf life, mold inhibitors will often be added to feeds, and those inhibitors cause all kinds of gut disturbances. If you feed corn on its own, it’s important to monitor it regularly for any contamination or mold that might appear. If you notice that corn you’re feeding has developed mold it is essential to dispose of it.
5. Corn is genetically modified – This point won’t be of great concern to everyone, however, many people are concerned about feeding genetically modified products to their horses. Almost all of the corn produced in the United States is genetically modified, particularly that being sold as animal feed. If you’re aiming to avoid GMOs in your animal feeds then corn is the first thing you’ll want to eliminate.