Figure 2: Comparison of the effects of administration of a cobaltised oral drench, a soluble vitamin B12 injection, a Co-containing intraruminal bolus, and a long-acting vitamin B12 injection on the serum vitamin B12 concentrations of sheep. Serum vitamin B12 >350 pmol/L indicates adequate vitamin B12 status, above which animals are unlikely to respond to supplementation in terms of improved performance or production.