Preparing Your Foal For Weaning
By Jeffrey Rolo
The horse-weaning period can be a highly stressful ordeal for you, the dam and the foal, but luckily there are steps you can take to make the period safe and less traumatic for all involved. It could actually be argued that proper preparation is actually more important than the actual execution.
One of the most common questions among first-time breeders is, "what is the best age to wean my foal?" The average weaning period begins anywhere from three to six months, depending on a variety of factors such as:
Nutritional Needs
You should not initiate the weaning unless your foal is already comfortable with eating grass, grain and hay. This is rarely a problem since most foals will learn by their dam's example and start experimenting with solids within a few weeks of being born. Your job will not really be to teach your foal to eat solids, but rather to ensure he eats enough at an early age. 
Once a foal reaches around three to four months of age his dam's milk will not be enough to sustain his nutritional needs, which is probably the prime reason most choose this period for weaning. This can either be a blessing or a curse, depending on how advanced your foal's feeding schedule was prior to the weaning.
You do not want your foal to live on a diet primarily consisting of his mother's milk and then suddenly toss him into a diet consisting of high protein grains and feed, because the sudden influx of protein can cause rapid growth. As great as such growth may initially sound, it could actually trigger developmental orthopedic disease (potentially causing your foal to become lame).
The key to safe growth rates and weaning is a gradual introduction of grains and roughage as early as possible, such that the foal's tastes and system are very acclimated to these types of feed by the time he is separated from his mother. This is generally done through "creep feeding," which is where you install a feeder designed so that a full-grown mare cannot access it. The foal's small size will permit him from eating the grain within while the dam's size will prohibit her from doing so.
Socialization
Ideally before you wean your foal you will already have provided him the opportunity to learn how to behave properly within a herd. In other words, your foal should have learned how to be a horse, developing the proper mannerisms, body language and instincts. These lessons can be learned from an alpha mare, older herd members, or most-often the foal's dam. Nature nearly always ensures this requirement is met, but two factors can potentially lead to the development of a foal that behaves more like a human than a horse:
