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.
Vitamins are organic compounds that are needed in even smaller quantities than minerals by the horse, although no less critical. Vitamins can be divided into two groups, the fat soluble vitamins A, D, E and K and the water soluble C and B-complex vitamins.
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.