A comparison of the vitamin B12 and cobalt contents of livers from normal lambs, cobalt-dosed lambs, and others with a recent history of mild cobalt deficiency disease

摘要

Summary Vitamin B12 and cobalt concentrations were determined in the livers of 3 groups of lambs. One group, not given supplementary cobalt, was grazed on cobalt-sufficient pasture. A second group was dosed at the rate of 7 mg Co a lamb a week and grazed on pasture that had remained generally low in cobalt until about 2 months before the end of the trial. The third group was given no supplementary cobalt, grazed the same pasture as the second group and showed evidence of mild cobalt deficiency disease followed by a recovery within the last 2 mon ths of the trial. The mean vitamin B12 value for livers from unsupplemented lambs on cobalt-sufficient pasture was 0.65 εg / g of wet tissue. Cobalt dosing approximately doubled the mean vitamin B12 concentration in livers from lambs grazing pasture previously low in cobalt to a level approaching that for unsupplemented lambs on cobalt-sufficient pasture. The mean vitamin B12 value for livers from the group with a previous history of cobalt deficiency was 0.31 εg ...