A typical hay sample report shows the hay’s megacalories per pound in addition to the sugar and starch content. A megacalorie is 1,000 kilocalories, and a kilocalorie is what we know as a calorie. The rest of this article will use the familiar term of calorie.

My recent hay sample of brome hay says it has .88 megacalories, or 880 calories, per pound. If my horses are eating 20 pounds per day, they are getting 17,600 calories a day from their hay, which is wee bit over the 15,000 calories a day that the National Research Council is suggesting for a sedentary 1,000-pound horse, which might explain the big rolls of fat on my horses’ sides. For years with these hay results, I’ve been looking at the sugar and starch content to determine if I had the right hay. But, now I’m taking into consideration the calorie content, and the horses are getting too many calories. Reviewing my hay tests going back to 2004, the calories per pound all fall within a similar range. This particular hay is not extreme.

As for feed, the Animal Health Foundation, a laminitis research foundation, compiled the calorie amounts of many common equine feeds and distributed the list in 2007. I’m attaching a copy of that here since I can’t find it online. Most feeds have 1,000 to 1,500 calories per pound. My horses are getting a pound each of forage supplement.

The hay is particularly frustrating because my horses go through two flakes of hay at each of their three meals in no time and look at me as if I’m starving them. And, my strategy for exercising them has been to spread the hay out in several areas so they have to walk to get it. I can’t leave much of a pile in each place if I’m trying to stick to the two flakes per horse rule. And if I leave too small of a pile on a windy day, it just blows away. To find out that I’m 2,600 calories over their limit while struggling to stick to two flakes per horse per meal makes it all feel a little hopeless.