Hay

When the grass is limited, as in our Western Australian summers, horses still need the bulk food that grazing provides. Meadow hay is far superior nutritionally than the extensive use of oaten hay, so commonly used.

It is better to give the horse several small amounts over a day, than one large amount once. This keeps up a constant feeding all day, with only short intervals of fasting in between.
 

Vitamin A

Horses do not need vitamin A as they convert it from beta carotene. So they do need beta carotene. This is available in green and orange foods, such as grass and carrots.

The best way to supplement beta carotene is to give plenty of carrots when there is no green grass available.
Lucerne (alfalfa) also contains a large amount of beta carotene, but the farming methods used to grow it means most lucerne is highly toxic, as it is sprayed so frequently with insecticide.
All vitamin A comes from animals, normally the liver. Most horse vitamin A supplies are from fish liver. As the horse is a herbivore, and doesn’t normally go deep sea fishing, this supplement can be harmful. The British discovered the hard way, that you can’t feed herbivores (cattle) meat by-products and get away with it, as they found out to their cost with the Mad Cow disease.
 

Minerals

It is also a good idea to supplement the mineral intake, as our soils aren’t highly fertile. As minerals are more easily digested in plant form, kelp provides the ideal food source of minerals.
Dose - One rounded dessertspoon per day for a horse in low to medium work is sufficient, more for those in high work.
Available - from stock feeders.

Oil

To ensure the horses can shed their winter and summer coats easily, some form of oil is essential in their diet. This can be in the form of seeds, such as sunflower, or linseed (soaked overnight but not cooked).
Dose - One third of a handful of sunflower seeds or a measure of linseed as required daily.
Available - Sunflower seeds are available from most stock feeders.

Even with good living conditions and a good relationship with you, horse are prone to some common ailments.