In the production process of chickens, in addition to meeting the needs of chickens for carbohydrates, proteins, minerals, vitamins and other major nutrients, it is also necessary to add some trace elements to their feed. In particular, the three trace elements of iron, copper and cobalt are indispensable elements of chicken body hematopoiesis. Adding proper amount of iron, copper and cobalt to the chicken's feed not only promotes its health, but also improves the performance of the chicken. Addition amount: Chickens within 8 weeks of age were supplemented with iron (ferrous sulfate) 80 mg and copper (copper sulfate) 4 mg per kg of feed. Laying hens add 90 mg of iron (ferrous ferrous sulfate) and 5 mg of copper (copper sulfate) per kilogram of feed. AVi China Feed Industry Information Network - based on feed, serving animal husbandry