Indeterminate nodules are the only type found in Caesalpiniodeae and Mimosoideae and the most common type in Papilionoideae (Sprent, 2001; p. 32). As a result of the variety of ways the plant is infected by rhizobia, there are different types of nodules.
Minerals are inorganic nutrients that are needed in relatively small quantities by the horse. The essential major minerals are calcium, phosphorus, magnesium, sodium, chloride, potassium and sulfur. The essential trace minerals needed are iron, zinc, copper, selenium, manganese, iodine, and cobalt.
In addition to the amount of mineral required daily, the ratios of minerals with each other and with other components of the ration are important due to effects on absorption, metabolism and/or excretion. In particular, a critical consideration in mineral nutrition of the horse is the calcium to phosphorus (Ca:P) ratio.