单选题 指根据畜禽的不同种类、性别、年龄、体重、生理状况、生产目的与生产水平等,科学地规定每头动物每天应供给的能量和各种营养物质的最低需要量. ( ) means that according to the different species, sex, age, weight, physiological condition, production purpose and production level of livestock and poultry, the minimum requirement of energy and various nutrients that each animal should be supplied daily is scientifically specified