Trace mineral testing

Late autumn is the time to ensure trace mineral status and particularly copper levels are adequate heading into winter and then spring. Copper levels may be reduced with zinc treatment over summer and autumn and then liver stores typically decrease over winter and early spring. Testing now allows fine-tuning of maintenance dose rates through the water or feed specific to your farm and herd prior to the next season.

Liver biopsies are the best method for determining copper stores in the body as there is a huge variation between blood and liver copper samples. Measuring blood copper levels alone does not give an accurate measure of how much copper is stored in the liver. The best animals to collect samples from are those that are representative of the herd (rather than cull animals sent to the works). We also recommend sampling replacement animals at grazing and it is safe and simple to collect liver samples from calves and heifers.

Selenium and B12 can be measured at the same time using either liver or blood samples. Blood samples can also be measured to check for liver damage from facial eczema and to measure zinc levels as a guide to the effectiveness of facial eczema prevention.

Contact your local clinic with any questions.

Dr Ilyse Jennens - Branch Manager BVSc (Dist) MANZCVS Medicine of Dairy Cattle