Co是动物营养必需的微量元素,它是维生素B_(12)的构成成分,还能以辅酶的形式影响酶的活性,参与许多生化反应。畜禽缺Co主要表现为食欲不良、精神萎顿、幼畜生长停滞、成畜消瘦。Co对于鱼类是必需的也已被证实。据Shabalina报道,用虹鳟稚鱼进行试验,平均每尾投以0.5mg的Co,结果试验鱼的生长比对照组快;用2龄鱼低Co饲料喂养的虹鳟,其 Co is an essential trace element for animal nutrition. It is a component of vitamin B_ (12), and can also affect enzyme activity in the form of coenzyme and participate in many biochemical reactions. Lack of Co in livestock mainly manifested as poor appetite, mental exhaustion, stagnation of young animals, adult weight loss. Co, which is essential for fish, has also been demonstrated. According to reports from Shabalina, rainbow trout juveniles were tested with an average of 0.5 mg of Co per tail, resulting in faster growth of test fish than controls; rainbow trout fed with 2-day-old fish with low Co diet