Cows: grass tetany - low blood magnesium, reduced intake, nervousness, muscular twitching, tetany, death (0.1 vs. 0.2% requirement

• 母牛：缺镁症-低血镁、减少采食、神经过敏、肌肉颤动、四肢抽搐、死亡（需求0.；1对0