The absence of trace elements manganese and zinc in meat donkeys can cause slow growth. The trace element manganese is distributed in all body tissues, mainly in bone, kidney, liver, spleen, pancreas and pituitary. Manganese acts as an enzyme activating factor or component in the metabolism of carbohydrates, lipids, cholesterol, and proteins and participates in the formation of chondroitin sulfate in the bone matrix, and is an essential substance for maintaining the normal metabolic functions of the brain. Manganese deficiency will grow slowly, it will reduce the intake of food, bone abnormalities, and ataxia. The lack of manganese will also affect the breeding of the donkey, so that the estrus of the female donkey is not obvious and the pregnancy is easy to abortion in the early stage of pregnancy. The content of manganese in vegetable feedstuffs varies greatly. Green feed and bran contain rich manganese. Gramineous seeds and roots, tuber content is low, animal feed contains very little manganese. Production is often supplemented with manganese sulfate, manganese carbonate and manganese oxide. Skeletons are the main storage organs for zinc, and the amount of zinc in the coat is also higher. Zinc is involved in the composition of enzymes in the body and has an effect on the formation, storage, and secretion of hormones. Zinc deficiency causes loss of appetite and slow growth. A long-term lack of zinc in the donkey would completely stop the testicular dysplasia and sperm growth, and the female donkey's zinc deficiency rate would be reduced. The plant feed contains more zinc, and the root and stem feed is poor. Gauze Balls,Cotton Gauze Balls,Absorbent Gauze Balls,Disposible Gauze Ball Zhende Medical Co.,Ltd , https://www.zdmedicalproducts.com