A horse’s diet should always be based on forage, whether fresh (i.e. grass) or preserved (i.e. haylage or hay). Most horses require between 2-3% of their bodyweight as dry food per day. If your horse needs to lose weight it may be necessary to restrict their total daily dry matter intake slightly. However, you should always speak to your vet before limiting your horse’s forage intake as, if not managed correctly, this can increase the risk of serious digestive and health problems.
Some of your horse’s daily ration will be provided as hard feed (concentrates), but ideally as much as possible should be forage. When calculating the amount of forage your horse needs, it’s also important to remember that even preserved forage contains some water, for example hay usually contains around 15% moisture, so 1kg of hay actually provides 0.85kg of dry matter.
As most horses are turned out for at least part of their day determining the exact amount of preserved forage they need, if any, can be difficult. As a guide, if your horse is never turned out, or is turned out only for few hours, then the entire forage portion of the diet should be provided as conserved forage. However, for horses that spend 50% of their time at grass, or that are permanently out on a semi-starvation paddock, this can be reduced by half.