Normal forage (grass, hay, silage) is rich in potassium. Even though the potassium requirements of horses are known, we have chosen not to include potassium requirements in PC-Horse, because the roughage in the ration will, under normal practical conditions, provide a large excess of potassium. During extreme physical activity (endurance riding and other high intensity competitions) it is recommended to use electrolyte (mineral) mixes with potassium to replace sweat losses. Molasses from sugar cane is also a good source of potassium.
In plant cells potassium (K+) is found together with various organic anions (ions with negative electrical charge). A dietary surplus of potassium must be excreted with urine and feces, and is accompanied by anions, such as bicarbonate or chloride. A high excretion of bicarbonate leads to an alkaline urine, which is typical for herbivore animals (plant eaters). The potassium content of the feed is part of the cation-anion balance (DCAB) which PC-Horse calculates for a feed or a complete ration (see later).