An Evaluation of Lon g Acting Injectable Microencapsulated Vitamin B 12 to Prevent Cobalt Deficiency in Grazing Ruminants

The efficacy of a long acting Vitamin B12 consisting of microencapsulated Vitamin B12 in a polymer of organic acids, when injected subcutaneously or intramuscularly into the anterior neck region, was evaluated in lambs and calves. The serum and liver Vitamin B12 concentrations of the treated lambs (0.12 to 0.25 mg Vitamin B12 /kg LW) were increased and maintained, being at least 40% higher than the untreated animals at days 210 or 249. In Co deficient lambs an injection of microencapsulated Vitamin B12 increased tissue Vitamin B12 concentrations as well as their growth rates (75 v 175 g/day). Likewise the serum and liver Vitamin B12 concentrations of treated calves (0.12 to 0.30 mg Vitamin B12 /kg LW) were increased and maintained, when compared to untreated animals for at least 110 and 150 days respectively.