So this mare would need a minimum of 18.33

pounds of hay per day. What if she were in highintensity work, such as upper-level eventing or racing? Then she would need 1.25 percent of her body weight, or 13.75 on a dry matter basis, which is 15.27 pounds of hay. Remember that a horse in higher intensity work needs more calories, so his minimum hay requirement will be lower but the balance of his diet will be rounded out with a higher percentage of high-calorie grain/concentrates.

Weighing hay is a critical part of this process.

However, I know that in practice hay is often fed by the flake rather than the pound. This often leads to imprecision. For example, flakes of grass hay generally weigh less than legume-based flakes of similar size. Even bales of the same type of hay can have different weights. Leaves generally pack better than stems, so as plants mature and develop a higher proportion of stems to leaves, bales generally become less dense and lighter.

Weighing hay is easy. You can do this by stepping on a scale yourself and noting the weight, then stepping back on while holding the hay and doing a quick calculation. Or you can hang a fishing scale from the rafters of your hay storage area and weigh hay in a net.

Resist the temptation to simply “eyeball” hay amounts. If you aren’t going to feed hay freechoice—giving your horse more than he’s going to eat before the next portion arrives—weighing his hay is absolutely necessary to ensure he’s getting enough. I realize many people don’t do this, but it’s the only way to be certain you’ve got it right.