FEED MATH…It’s really not that scary! 

Were you tempted to skip this when you saw the word MATH? Please keep reading- it’s not that hard. We’ll talk about determining how much commercial feed your horse needs and management techniques to help you feed him the best that you can in the most cost-efficient manner. We’ll just stick to commercial feeds for this article and talk about hay another time.

To make these determinations, first we need to gather some info. The next time you’re at the feed store, ask for a weight tape. You can usually get one for free. There are two kinds: the version that has been around forever with pound increments on it, and the one with inches. They look a lot like measuring tapes used in sewing and in fact you can use a seamstress tape. You’ll need to measure his heart girth and his body length in inches. Heart girth is basically over his withers and around his barrel where the girth would normally lie. The tape should be snug but not tight and your horse should be on a flat, level surface. Next, measure his body length from the point of his shoulder, on a straight line, to the point of his buttocks. The line will likely run uphill, and it may take two people to do this. This is NOT his blanket measurement! Take out your smart phone or a calculator and plug in the measurements as follows: heart girth X heart girth X body length. Yes, it’s a HUGE number. Now divide that by 300 for your horse’s weight. If you have done your measurements carefully, the result will be very close to his actual weight. (Divide by 301 for a yearling, 280 for a weanling, and 299 for a pony.)

Next, it is important that you know how much you are feeding your horse…BY WEIGHT. This means by ounces or pounds, not “a handful” or “just a taste” or “two scoops” or “one coffee can.” Why? Because feed bags generally tell you how much to feed your horse by weight, not volume. And your handful may be larger or smaller than mine, winter gloves make a difference, and “just a taste” is no measurement at all. What are you using for a scoop? Is it a 3-quart scoop or a 5-quart? Is it open or enclosed, meaning that that it resembles a square milk carton? Are you leveling it off or heaping it as much as you can? And coffee cans…which one? Are you using the ones from the ‘70s that held 16 ounces of coffee or the later ones that hold only 12 ounces? Is it a metal can or one of those small (or really large) plastic ones? There are no standard-sized coffee cans.

As you can see, there are many variations when we talk about how you measure your feed. So how can you know how much he is getting? Whatever container you are using, measure out one typical meal, place it in a plastic baggie, and take it to your local feed store. Ask them to put it on the scale and tell you what it weighs. Any feed store that sells bulk product must, by state regulations, have a licensed and accurate scale. Don’t use the hanging scale by the bulk bin; that won’t be as accurate. You can also take your sample to the post office and ask a clerk to weigh it, but you may get funny looks.

Do you remember this riddle? Which weighs more, a pound of feathers or a pound of lead? Of course, the answer is that they weigh the same. A pound is a pound. Beware of applying this to VOLUME though because it doesn’t ring true. A “coffee can” of pellets doesn’t weigh the same as a can of textured or sweet feed- it’s heavier. And a “coffee can” of extruded feed is lighter than both. A can of extruded feed may look like the same amount as a can of pellets when you pour it in his bucket, but the weight is less. Pet peeve alert…a one-pound coffee can does indeed measure one pound…of COFFEE. It’s not meant to measure out a pound of horse feed. The photo with the jars that have been filled to the top illustrates this well. Each jar holds a quart, but the weights range from one pound of the extruded/fiber supplement (left) to one pound, 10 ounces of the alfalfa pellets (right.) The pelleted ration balancer is one and a half pounds, and the textured senior feed is one and a quarter pounds. Same volume, different weights. Now compare that photo to the one of the four jars that each hold one pound of feed. You can clearly see that the volumes are different although the weights are the same.

You might think that all pelleted feeds or all textured feeds weigh the same per volume, but that is not the case either. Just for fun, I compared the measuring scoops provided by three different feed companies. They each had lines marked on the cup to tell you how many half-pounds or pounds of a particular feed that they could measure, and they were all different. If you are using Company A’s measuring scoop for a pound of senior feed, it won’t necessarily measure out a pound of Company B’s senior feed. You could be feeding more- or less- than you think. If you look at the photo of the two jars with two different ration balancers, you can see this. Each jar has one pound, but the volumes differ.

You may be wondering; does it really matter? Do I have to weigh the feed for every meal? Not really, if you are consistent with the amount that you feed at every meal. The point is that you should know how much you are feeding by weight so that you can follow feeding directions on the bag and ensure that your horse is benefitting from his feed.

Let’s get back to the feed math. Now you have the two most important pieces of information that you’ll need: your horse’s weight, and how much feed by pound that he is eating. Let’s look at a feed bag.

Feed companies differ in the way that they convey information on their bag or tag, but they all have a couple factors in common. They will tell you the “audience” that the feed is targeting. It may appear as “breeding stallion”, “lactating mare”, “performance horse”, “maintenance horse”, “horses older than one year”, ponies and minis. Some may be more specific and break this down into activity levels such as light, moderate, or heavy exercise. Then the bag will suggest how many pounds (not cans, handfuls, or scoops) to feed the horse based on his weight and activity level. It may appear as “per 100 lbs” or “per 1000 lbs” or even in kilograms if it is a European feed. Here is where we need to do a bit of math.

If you’ve determined that your horse weighs 1000 pounds, then you would start with the recommendation for a 1000- pound horse (or 10 times the rate if the feeding level is X per 100 pounds of body weight.) If he weighs 900 pounds, then multiply the rate for a 1000-pound horse by 0.9, because his weight is 9/10 that of a 1000-pound horse. (Or multiply by 9 if the rate is X per 100 pounds of body weight.) If he weighs 1200 pounds, then you would multiply the 1000-pound rate by 1.2 (or 12 if using the 100-pound rate.) Remember that the recommendation is for the total amount of feed per day. You will divide it into two or more feedings depending on your schedule.

Now let’s stop for a moment to consider two very important points. First, you should never increase, decrease, or change a horse’s diet quickly. His gut can’t keep up and he won’t be a happy guy. Neither will you if you have to call the vet for a colic exam. ALWAYS make feed changes very slowly. Many vets recommend 10-14 days. I’ve taken as long as a month for an ulcer-prone TB mare.

Second, the rates on the feed bags are RECOMMENDATIONS and not carved in stone. Your horse is an individual and should be fed as such. He may need less if he is an air fern, more if he is a nervous horse or a hard keeper. It will take a bit of time to determine if the rate is too much, too little, or just right. If, however, you find that you are feeding a pound per day while the feed bag recommends five, you would do better to choose a different feed. If you are feeding at a fraction of the bag’s specifications, then your horse is not getting the full complement of vitamins and minerals listed on the bag. Consider a “lite” feed or good quality hay and a ration balancer. On the other hand, if you are feeding a lot more than the recommended rate, he may be a good candidate for a higher fat feed or a fat supplement for the extra calories that he needs. (Of course, you’ve followed a good deworming program and have had his teeth maintained regularly.) A horse should not get more than five pounds of any concentrated feed at one time (that means commercial feeds and whole grains, not hay.)

Now let’s move to the math that directly impacts your wallet. We’ll look at figuring the cost per pound and the cost per day to feed, and why each is helpful info.

Most feed bags, but not all, weigh 50 pounds. Some may weigh 40 pounds, and some of the European feeds come in odd weights like 44 or 35 pounds. Many balancers and other supplements may weigh less than 50 pounds. To get a true picture of the cost of feeding your horse, start with the cost per pound, not the cost per bag. To determine the cost per pound, divide the cost of the bag by the weight.

Now you have the information you need to determine the cost per day. Please note that this is cost per day, not cost per feeding. It should be the total of all the meals that you feed in a day. I find this useful because most of the time you won’t be able to compare feeds perfectly as the feeding rates will differ. Let’s look at a couple ration balancers as an example. They tend to be the most expensive feed product per pound but not necessarily per day, as you feed less than you would of a commercial feed. The role of ration balancers is to fill in the nutritional gap if you are feeding a forage diet, or if you are giving so little feed that your horse isn’t getting all the nutrients that he needs, or if you are feeding straight grains such as oats and your horse is lacking nutrients. To keep things on an even footing, we’ll pretend that we are using this product to balance a forage diet.

Since most ration balancers are around 30% protein, we can say that these are comparable. They differ in the amount of fat from 3% to 5%, and in the amount of fiber from 3% to 6%, but to be honest, you shouldn’t be choosing ration balancers based on their fat and fiber content.

Product A recommends one pound per day for a 1000-lb horse who is at maintenance level (as in not doing any work.) Our second choice, B, recommends one to one-and-a-half pounds for the same horse and our third choice, C, recommends 0.08 – 0.3 per 100 pounds of body weight, or 0.8 to three pounds for a 1000-pound horse. We’ll pretend that our horse weighs 1000 pounds, but if you yours weighs more or less, be sure to adjust accordingly using the math above.

A costs $36.00 per 50-lb bag, which works out to 72 cents per pound ($36 divided by 50 pounds) and the recommendation for your 1000-pound horse is one pound per day. You pay 72 cents per day for the balancer that your horse eats.

B costs $34.25 per 50-lb bag, which is 69 cents per pound. If you feed your horse according to the recommendations, you’ll be giving him one pound to one-and-a-half pounds at a cost of 69 cents to $1.04 per day.

C costs $26.00 for a 40-lb bag, or 65 cents per pound. For a 1000-pound horse, your feed rate would be between 0.8 and three pounds, at a cost of 52 cents to $1.95 per day.

Okay, you’re thinking, so it’s a few cents difference for the lowest feeding rate. What’s the big deal? Let’s say it’s summer now and you bump up your horse’s feeding rate because you’re riding more, and he needs more protein to maintain muscle mass. The rate of feed for moderate activity for A is two pounds for a 1000-pound horse. Your horse is now getting two pounds per day at a cost of $1.44. Balancer B recommends feeding 1.5 to two pounds, so your cost is $1.04 to $1.38. And C recommends 0.15 to 0.3 pounds per 100 pounds, or 1.5 pounds to three pounds, at a cost of 99 cents to $1.95. It’s interesting that C, which is the cheapest bag, could end up costing you either the least or the most per feeding. (And remember, if you are using Company A’s half-pound measure to scoop out Company B’s feed, you may not be feeding enough or may be feeding too much.)

You can use the same process for inexpensive feeds too. Don’t worry- we aren’t going to do the math because you now know how to do it yourself! Let’s suppose that you buy XYZ’s “Basic Horse Feed 10% Protein.” It’s low protein, low fat, and moderate fiber. But at $15 per 50-pound bag, it’s cheap. Hold on though- the feeding rate is nine pounds per day for your horse! That’s $2.70 per day. But his topline looks weak and your trainer suggests that more protein would be beneficial. And his coat doesn’t look that great and he could use some more weight, so you think that adding some oil or other fat supplement will help. And the farrier suggests adding hoof supplements to his diet because his feet are getting punky. And the vet is concerned that he isn’t getting enough vitamin E and selenium, which we know is deficient in our area. Off you go to the feed store to stock up on these supplements. While you’re there, ask about the price of a higher quality feed, read the bag tag, check the feeding rate, and do the math. You may be pleasantly surprised to learn that the more expensive feed, with its higher quality ingredients and supplements, is a better deal…and you may be able to feed less of it.

You may be tired of numbers now, so we’ll finish up with one more short example. Let’s say your horse is having trouble maintaining his weight. You favor extruded feed and you feed him two coffee cans per meal, twice a day, but he just doesn’t seem to be gaining! You check the bag tag and realize that he should be getting six pounds per day, so you increase his feed to three coffee cans per meal, twice a day, because…hey, it’s a one-pound coffee can, right? Not really. That is a step in the right direction, but he still isn’t getting six pounds per day because that particular coffee can holds 0.85 pounds of extruded feed, not a pound. He’s short almost a pound per day, which translates into 1600 kcal for that particular feed. Depending on his activity level and size, that could be 10% of his total caloric need per day. Maybe he’s not a hard keeper- it could just be that he needs more groceries.

In summary, feed math isn’t hard. Measure his heart girth and body length and use those figures to determine his body weight. Determine the weight of the feed that he is eating, not the volume. Then use those numbers and the information on your feed bag to determine how much he should be eating and adjust up or down depending on his particular needs. Remember to make any feed changes slowly, and always offer free choice salt and fresh clean water. If you have more questions, ask someone at your friendly neighborhood feed store!

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