目前养殖业日益向规模化、集约化方向发展,使用抗生素、维生素、激素、金属微量元素已成为保障畜牧业发展必不可少的重要手段,尤其是过去传统用于预防和治疗畜禽疾病的不少兽药被作为饲料添加剂在大量广泛使用。据报道,在美国大陆有80%的食品动物,在其一生中或多或少地服用过兽 At present, the aquaculture industry is increasingly developing towards large-scale and intensive use of antibiotics, vitamins, hormones and metal trace elements, which have become an indispensable means of ensuring the development of livestock husbandry. In particular, the past traditionally used for the prevention and treatment of diseases of livestock and poultry Little veterinary medicine is widely used as a feed additive in large quantities. It has been reported that 80% of food animals in the continental United States have consumed beasts more or less throughout their lives