Cobalt participates in the synthesis of vitamin B12 in animals' bodies. Animals lacking cobalt will affect the synthesis of vitamin B12 by animalcule in alimentary canal so that leads to anemia. For ruminants, lacking cobalt can lead to inappetence, retarded growth, anemia, thick and disorderly clothing hair, reproduction prevented. Specifications: 1) CoSO4.H2O: Co≥30.0 2) Cobalt sulfate thinner: Co=1.0±0.05, Pb≤0.004, As≤0.001 3) Cobalt sulfate thinner: Co=5.0±0.10, Pb≤0.004, As≤0.001