A comparison of vitamin B₁₂ concentrations in livers and kidneys from cobalt-treated and mildly cobalt-deficient lambs

Abstract

Vitamin B₁₂ concentrations were determined in the livers and kidneys of (1) lambs treated with cobaltic oxide pellets and (2) untreated lambs grazing cobalt-deficient pastures.

Vitamin B₁₂ concentrations in livers and in kidnevs of cobalt-treated lambs ranged from 0.44 to 1.6 µg;/g (mean 0.84 µg/g) and from 0.25 to 0.75 µg/g (mean 0.52 µg/g) respectively. In livers and kidneys of presumed mildly cobalt-deficient lambs concentrations ranzed from 0.09 to 0.16 µg/g (mean 0.12 µg/g) and from 0.19 to 0.26 µg/g (mean 0.23 µg/g) respectively. For cobalt-sufficient lambs liver/kidney vitamin B₁₂ ratios were all greater than one. For cobalt-deficient lambs ratios were all less than one.

Factors that may limit the diagnostic value of vitamin B₁₂ concentrations, particularly in kidney, are discussed.