How Much Grain Should I Feed my Colic-Prone Horse?

Q. My horse is 19 years old and is sometimes colicky. I think I’m giving her too much grain—I use a measuring cupful, and she weighs 800 pounds. Can you please help me? I’m worried!

—via email

A. Colic is a potentially life-threatening condition, and I applaud you for wanting to get to the bottom of what may be causing these episodes. I would encourage you to discuss with your veterinarian what the potential causes might be because, depending on the type of colic your horse is suffering, the two might not be related. Colic should always be brought to your veterinarian’s attention especially when it is repetitive.

As for whether you are feeding too much grain, this is very hard to tell from the information provided. I’m unable to make an accurate assessment without knowing your horse’s current body condition, work level, type and amount of forage consumed, and the type and amount of grain you’re feeding. What I can do, however, is to provide you with some information that will allow you to determine whether your horse needs grain.

Step 1: The first place to start is to accurately determine your horse’s weight. Weight tapes will give you a rough idea but a more accurate method is to uses the horse’s girth circumference and length.

Step 2: Once you have determined your horse’s weight the next step is to assess body condition. Is the horse’s weight good for him or is he too thin or too fat? To do this you can use a technique called body condition scoring where you run your hands over six areas of the horse’s body, feeling the amount of fat cover and comparing it to the descriptions on the provided chart. Ideally you would like an aged horse to be between 4 and 5 on the Hennecke scale. If your horse is below a 4, you need to add more calories the ration. If your horse is over a 6, you need to remove calories.

I should caution that if your horse is underweight you should determine the cause. Is it just a lack of calories, or does the horse has an internal parasite burden, dental issues, or some other condition you and your veterinarian should address? Similarly if the horse is overweight care needs to be taken in reducing the calorie intake because a certain amount of food consumption (ideally 1.5% of body weight or higher) is necessary to maintain gut function. Please discuss any body condition score concerns with your veterinarian.

Step 3: Next, take a look at what you are currently feeding your horse. Is the majority of the ration forage? Does he have free access to good quality pasture, or are you meeting his forage requirement with other sources such as hay? If feeding hay, are you providing at least 1.5% of his body weight per day as hay? If so, is he able to maintain his weight just from consumption of forage, or does he require calories from a more energy dense source to maintain an ideal body condition?

If you determined that he is overweight and you are currently feeding grain, this would suggest that the grain is unnecessary. Conversely, if you decide your horse is underweight, first look at increasing forage intake as a source of extra calories. If that fails to add the desired weight, then look to more calorie-dense feeds.

Typically feeds high in readily available complex carbohydrates, such as beet pulp and soybean hulls, as well as those with a higher fat content tend to be safer options for weight gain versus those high in starch-filled grains. This is due to where they are digested in the horse gastrointestinal tract and the fact that if starches reach the hindgut undigested then can disrupt microbial fermentation and cause colic.

Even if you decide that your horse needs no additional calories, you might want to add a ration-balancing feed to ensure that any nutrients not provided by your forage are available to your horse. Ration balancers are feeds with low calorie content and extremely nutrient dense, and as such have a small serving size—typically between 1-2 pounds per day for an average 1,000-pound horse. They provide a source of quality protein as well as trace minerals and vitamins often lacking in forage. These ration balancers are also a good choice if you are someone who likes to feed unfortified supplemental feeds, like straight beet pulp or rolled oats, as they add the otherwise missing nutrient fortification.

When selecting a commercial feed it is vital that you feed it the way that the manufacturer recommends. To determine the recommended serving size you need to know the horse’s weight and work level. Feeding directions are generally given in pounds and, therefore, it is important to actually weigh the amount you are feeding. If you feed less than the manufacturer recommends, you will not be feeding your horse a balanced diet. If weighing your feed every day is not realistic, measure it one time into a cylindrical container, mark the amount needed, and then in future fill to the marked line to ensure you are feeding the correct amount. Assuming your horse’s body weight is 800 pounds, if you determine that more than about 4 pounds of supplemental feed per day is necessary, you should break it into at least two meals. This will make sure the digestive tract is not overwhelmed and will reduce colic risk.

If you still have concerns about what to feed your horse or the amounts necessary I recommend enlisting the services of a qualified independent equine nutritionist.