The so-called "bulk elements" include the minerals calcium (Ca), phosphorus (P), sodium (Na), magnesium (Mg), potassium (K). The so-called "trace elements" include iron (Fe), copper (Cu), zinc (Zn), selenium (Se), manganese (Mn), iodine (J), cobalt (Co) and molybdenum (Mo). Quantitative elements - required by the animal in larger quantities - are stated in the feed in g per kg or %, trace elements - required in the smallest quantities - in mg per kg or ppm (parts per million).
Bulk and trace elements fulfil essential tasks in the body as building and operating materials and are also components of animal performance products (milk, meat, eggs, foetus). The bulk elements usually have multiple tasks, whereas the trace elements have special tasks. They are significantly involved in the formation of the body's own active substances. The individual elements are partly interrelated with vitamins and are components of digestive enzymes or the body's own hormones. They take on tasks as accelerators (catalysts) in metabolic processes, for maintaining the osmotic pressure of the cells (very important for the transport of substances and fluids), as regulators in the digestion of food or in the sexual cycle. If these elements are supplied in insufficient quantities or in the wrong proportions, deficiency symptoms can occur, including skeletal damage and fertility problems. However, feeding should not be limited to preventing extreme deficiency situations. The animals should also perform, whether in the form of animal products such as milk in the case of farm animals or in the form of physical performance as in the case of sport and leisure horses as well as breeding horses. Therefore, the supply of animals with bulk and trace elements must also take these performance demands into account in order to ensure high health.