At birth . . .
your foal should weigh approximately 10 percent of his dam’s weight. For example, if your mare weighs 1,000 pounds, your foal is approximately 100 pounds.
From days 7 to 28 of life . . .
calculate your foal’s weight by measuring his heartgirth, subtracting 25, and dividing the result by .07. (To determine your foal’s heartgirth, use a cloth tape to measure around his barrel at the point just behind his withers.) Here’s the formula:
Heartgirth (inches) – 25 = Weight (in pounds)
divided by 0.07
From days 28 to 90 of life . . .
use the same formula, but add 10 percent to the result.
Barb Crabbe is an Oregon-based equine practitioner who breeds performance horses.
This article first appeared in the April 2000 issue of Horse & Rider magazine.