Does your horse need grain?

We seem to automatically assume that all horses have to eat grain. Let’s look at what your horse really needs to stay healthy!

Many people believe that horses and grain go hand-in-hand. Most barns feed grain meals to their horses two to three times a day. But does your horse actually need it?

Whether he truly needs grain depends quite a bit on what function he serves, as well as your personal philosophy. There are many reasons people give their horses grain: it could be as a treat, added to feed supplements, just in case they ever have to give medication, or because they think horses need grain for nutrition. Other reasons to feed grain, especially for high performance horses, are to avoid “hay belly”, and for calories.

There are three things to consider when analyzing a horse’s ration: caloric needs, calcium/phosphorus ratio, and protein content of the diet.

1. Caloric needs

If the average horse weighs 1,000 pounds (455 kg), he needs to eat 15,000 Kcal a day to maintain his body weight. This average horse eats 2% of his body weight daily in hay, which amounts to about 20 pounds (9 kg). One pound of grass hay provides 800 to 1000 Kcal of energy. A horse in high levels of work will eat twice that – that’s 40 pounds of hay a day! Depending on where you live, a flake of hay can range from three to eight pounds – east coast hay being lighter than west coast hay. This means the high performance horse would need to eat over 10 flakes of average hay daily for enough calories to maintain body weight at high levels of work.

For this reason, owners of high performance horses look to other diets for energy-rich compact feeds. Grain is the usual choice as it provides 1.5 times more energy per pound than hay; a pound of grain is much smaller than a pound of hay. Diets high in grains can lead to digestive issues — to prevent stomach ulcers and colic, a horse’s ration should be less than 25% grain. For the average horse, this means 15 pounds of hay and five pounds of grain spread throughout the day; double that for the high performance horse.

Pasture horses have very little need for extra calories from grain. The pasture horse needs 20 pounds of hay only when grass isn’t available. Remember the rule of thumb – one horse per acre of grass. One acre of rich, well-growing grass will produce 28 acres of grass in a year. Given sufficient acreage, a pasture horse doesn’t need grain, only pampering. When grass is not available and hay is fed, it can be a good idea to supplement with a ration balancer, as hay does not have the same nutrition as grass.

2. The calcium/phosphorous ratio

Thus far, our discussion has only looked at caloric needs. Different grains are better balanced nutritionally than others. Some horse owners feed whole oats because that is what their families have done for generations. Other owners feed corn-based sweet feed, while still others seek out whole grain concentrates.

Calcium (Ca) and phosphorus (P) are important nutrients to consider in the equine diet. (Other nutrients are also important, but calcium and phosphorus are critical.) A good Ca:P ratio should range from 1:1 to 2:1. The entire diet (grass, hay, grain and supplements) should favor more calcium than phosphorus. Different hays do a decent job of staying close to the healthy range. Grass hay tends to be quite close to the ideal ratio of 1:1 (everyone’s hay/grass is different and will vary by year, season, weather and soil). Alfalfa will have higher calcium levels (4.7:1) than grass hay, which is why experts do not recommend feeding strictly alfalfa to horses.

However, as shown above, hay does not provide enough calories for high-level athletes. Grains are a great source of calories, but pure grains can unbalance the diet. For example, oats and barley have an inverted Ca:P ratio of 1:5, while corn runs 1:15! Owners could argue that a handful of grain won’t make a large impact on an otherwise balanced diet. However, thanks to portion size creep or increasing portion frequency, grain meals often turn into a large portion of the horse’s ration.

3. Protein needs

Protein is the third factor to consider in a hay-based diet. Mature horses need to eat a minimum of 8% protein; the active horse can do well with a 12% protein diet. Too much dietary protein may lead to respiratory illness in stabled horses as a result of excess protein excreted through the urine. Average hay can range from 7% to 10% protein concentration. Thus, whether or not your horse needs protein supplementation depends on the protein content of the hay. For this reason, many horse owners have their hay tested.

Unless your horse is a high performance athlete, grass and/or hay and an appropriate serving of a whole food supplement is plenty of nutrition for good health. The hardworking horse’s diet should be less than 25% grain to prevent colic. Careful selection of supplemental feeds must meet caloric needs as well as keep the Ca:P ratio balanced, and provide the right amount of protein. For most horses, grain is best as a treat, a little snack that creates a bonding experience with the owner. By keeping the above pointers in mind, this little snack does not need to disrupt the diet.