Introduction:
Selenium is one of the indispensable trace elements in the growth of animal, and its powerful biological antioxidant function cant be replaced by vitamin E. To improve the organism on the immune response selenium is also the most important trace element. At the same time selenium plays an important role to the organisms anti oxidative stress, etc. Compared with organic selenium source inorganic selenium exist many problems, such as the toxicity is stronger, biological utilization rate is low and the use of dose is difficult to grasp, while the organic selenium has lesser toxicity and higher absorptivity. According to the active transport mechanism organic selenium is absorbed and utilized sufficiently. It is applied to livestock and aquatic increasingly wide in recent years.