The emergence and treatment kinetic of cobalt deficiency in the sheep.

The emergence and treatment kinetic of the vitamin B12 deficiency was studied in 4 adult male Texel sheep bearing rumen fistulas. A natural meadow-grass, low in cobalt (0.04 mg/g of dry matter) was distributed freely to the animals. After the emergence of the vitamin B12 deficiency, the animals received every day a 10 ml solution containing 0.5 mg of cobalt in the rumen. The ingestion of a cobalt-deficient hay provoked a great decrease in the synthesis of vitamin B12 during the first week. The serum content decreases more slowly, the deficiency threshold being reached after 7 weeks. A serious deficiency is apparent 10 weeks after the deficient diet was first distributed. The treatment applied to the animals has a rapid and spectacular effect. The synthesis returns to normal 72 hours after the start of intraruminal cobalt infusions. The animals are no longer deficient after 24 to 28 hours of treatment.