Trace Element Supplementation of Livestock in New Zealand: Meeting the Challenges of Free-Range Grazing Systems

Figure 1

Comparison of the effects of administration or application of a selenised oral drench, a selenised vaccine, a Se-amended fertiliser, a Se-containing intraruminal bolus, and a long-acting Se injection on the blood Se concentrations of sheep. Blood Se >250 nmol/L indicates adequate Se status, above which animals are unlikely to respond to supplementation in terms of improved performance or production.