Now that the Facial eczema season has died down and cull cows are heading to the works, it is now the time to be thinking about copper supplementation for the coming winter months.

Copper is an important trace element in both sheep and cattle for proper development. It is required for bone growth, nervous system development, integrity of the immune system as well as development of the coat and much more. Deficiency can result in diseases such as swayback and osteoporosis, in addition to contributing to poorer growth, reproductive problems, scouring and ill-thrift. Cattle are more susceptible to copper deficiency than sheep.

In New Zealand, copper deficiency is usually associated with an increased pasture molybdenum (Mo) concentration, which disrupts the storage of copper in the liver. Even low pasture concentrations of Mo, which are common in NZ, reduce copper absorption and deplete copper stores. There is also a seasonal decline, with liver copper levels being lowest during the winter months.

Because of the reasonably narrow margin between deficiency and toxicity, it is important to get an idea of the copper status of the animals on farm before treating with copper.

The best times to monitor copper status are:

• Cull cows/ewes in autumn and culled growing cattle at any time
• Ewes in early autumn
• Pregnant cows in late winter by liver biopsy
• Rising one-year-old cattle in mid-winter by liver biopsyLiver biopsy is by far a better way of measuring the levels of copper. Copper is stored in the liver and so liver copper levels show the amount of copper available for the future. The copper is pushed into the blood from the liver, and these levels will only drop once liver stores are depleted, so while deficiency can be confirmed with bloods, it will not tell you how much is left for the winter.

  To have liver samples taken at the works, fill in a request form (available from your local Anexa FVC Clinic) and send it on the
  truck with the cattle, to be handed in at the works. Some freezing work companies also have forms with a space for this request, so when filling their form in, just request that the results are sent to us.

  Copper supplementation options include:

  • Copper bolus. Effective for six to nine months. This will also increase the copper status in the foetus and lamb from birth to 9 to 10 weeks of age if given in early gestation
  • Subcutaneous copper injection. Effective for one to two months, and dangerous if overdosed.
  • Copper added to drinking water using an in-line dispenser
  • Topdressing pasture in autumn or spring. Pasture should not be grazed until after rain, and pasture uptake can be variable.

    Call us at the clinic to discuss any questions regarding testing, supplementations or if you suspect deficiency.