Iodine is a component of the thyroid hormone thyroxine, which regulates the entire metabolism. Thyroxine contains approx. 66 % iodine. The iodine requirement of animals depends on the heat production of the body. With increasing body weight, the iodine requirement decreases. Iodine uptake can be negatively influenced by high calcium contentsin the feed, among other things. Iodine deficiency can occur especially in so-called iodine-deficient areas (e.g. mountainous areas). Iodine deficiency leads, for example, to weak animals and stillbirths, a decline in semen quality and hairlessness. Cereals contain little iodine. There are generally large fluctuations in the iodine content of plant-based feedstuffs. Dried pulp (by-product of sugar productionfrom sugar beet), for example, is rich in iodine. The iodine supply of the animals is ensured, depending on the need and type of feed, by a targeted iodine supplement in mineral form as sodium or potassium iodideor calcium iodate.