Vitamin B₁₂ and copper in blood serum and liver of hoggets in relation to cobalt and copper status of west coast South Island soils and pastures

Abstract

This study assessed the status of cobalt (Co) and copper (Cu) in yellow-brown earth (YBE) and pakihi soils, in pasture growing on these soils, and in serum and liver of lambs grazing for a year on the pasture. There had been no application of Co or Cu to YBE soils except in one instance, whereas these elements had been applied to pakihi soils at various times within the previous eight years since pasture establishment. Co in pasture was usually in the ‘adequate’ reference range category, although most of the soils were in the ‘responsive’ category. Cu in pasture was in the ‘marginal’ reference range. Co (as vitamin B₁₂) was usually adequate in serum and in liver. Cu was marginal in serum, but adequate in liver. There was only one pakihi soil — the Moana soil at Bell Hill — where, despite recent topdressing with CoSO₄, Co levels in liver were consistently in the marginal range.

Keywords:

• cobalt
• copper
• trace element
• soil
• pasture
• serum
• liver
• vitamin B₁₂