In my previous blog post on this topic, we explored the role starch plays in the horse’s diet. After (hopefully) warming you up to the idea of how useful this nutrient can be, I’d like to now dig in to how you can compare and contrast the varying levels of starch (and sugar*) in feeds and hopefully this information will help you compare and contrast to choose the best option for your horse.
Contrary to what you may have been told or read, most horses can tolerate a moderate level of starch each day. If you have a horse that has been diagnosed with a form of equine metabolic disease, you will need to limit your horse to a ‘low’ controlled starch and sugar diet….which includes forage (hay and pasture). Fructans, the sugars in forages, are too often overlooked when assessing the total diet of an EMS horse.
Even if your horse has not been diagnosed with EMS, it is still important to understand the starch level in his diet and take it into consideration for your overall program. Think you know how to compare starch levels from one feed to another? You might be surprised to find out that a bit of math is required. Simply comparing the percentage of starch on feed tags doesn’t quite tell the whole story. To get to a true comparison, it is important to factor in the recommended feeding rate, which is, after all, what the horse experiences.
Let’s compare two feeds that are marketed as ‘low starch’; one has a starch maximum guarantee of 7% while the other has a maximum of 11%. Pretty easy to tell which one is the lowest, right?
Look beyond the percentage to find what's really in the feed
Not quite. For our example, let’s say we have a 1,000 pound horse at maintenance level activity. Feed A, with 7% starch is recommended to be fed at a rate of 6 pounds per day, meanwhile, Feed B has a starch maximum of 11% and is recommended to be fed at a rate of 2.5 pounds per day.
Here is the formula to use: Starch % * pounds fed/day *454 (converts to grams) = grams of starch fed/day
Applied to our example scenario, here’s how the math works out:
Feed A: 7% starch x 6 pounds fed x 454 = 190.68 grams of starch per day.
Feed B: 11% x 2.5 pounds of feed x 454 = 124.85 grams of starch per day.
Wow – a big surprise! Not only is the 11% starch feed actually lower in grams of starch per day than the 7% product, the difference is actually rather significant given how different the percentages were. It is important to keep in mind that it all comes down to what your horse actually ingests, so understanding the recommended feeding rate in pounds and then weighing your feed to hit that mark is what will make the difference.
It’s also important to understand that horses who do not experience a form of EMS have a higher tolerance for starches and sugar in their diet…and in fact, the performance horse will actually need those nutrients to support their activity levels. It all comes to down to understanding what’s in your feed and how much you’re giving them.
*Though this blog article addresses ‘starch’ the same principles apply to determining the amount of other nutrients in a feed.