Effect of ingestion of soil on the iodine, copper, cobalt (vitamin B₁₂) and selenium status of grazing sheep

Abstract

AIM: To determine the impact of ingestion of soil on the iodine (I), selenium (Se), copper (Cu) and cobalt (Co; vitamin B₁₂) status of young sheep.

METHODS: Twenty young sheep were divided into two groups; one group was fed lucerne pellets, while the other group was fed lucerne pellets plus 100 g soil, for 63 days. At the end of the study the animals were blood-sampled, slaughtered, and the liver removed, and concentrations of I, Cu, vitamin B₁₂ and Se were determined.

RESULTS: The ingestion of soil significantly increased concentrations of I and vitamin B₁₂ in serum, but had no effect on concentrations of Cu and Se in serum/blood and liver, and vitamin B₁₂ in liver.

CONCLUSION: Ingested soil can be a significant source of I and Co (vitamin B₁₂) for grazing sheep.

KEY WORDS:

• Sheep
• soil ingestion
• iodine
• copper
• vitamin B₁₂
• selenium
• serum
• liver

Acknowledgements

I wish to thank Matthew Deighton and Peter Schreurs for technical assistance, and FertResearch for funding.