Do you know the trace element status of your sheep? 

Copper, selenium, cobalt and iodine all affect growth and reproduction, animals need the right amount for their bodies to work properly. New Zealand soils and pasture can be deficient in these trace elements, and prevention of deficiency in the grazing animal is the best approach. You can find out about your sheep with an assessment using blood samples and/or liver biopsies. You can also have an analysis of your pasture.

Once you know the levels of the trace elements in your animals, there are a variety of ways they may be supplemented. Selenium and cobalt can be applied in the fertiliser to lift levels in the pasture. They can also be given directly to the animal either orally or as an injection and may be a long or short acting product. Your treatment decisions will depend on the level of deficiency (if any) and the length of time you are aiming to improve the levels for. For example a lamb going to the works in 6 weeks may only need a short acting drench, whereas a ewe carrying lambs may need a long acting slow release bolus.

You might say, well if we are deficient in these trace elements, why don’t I just give them to the sheep and not bother about testing? Unfortunately, it is not that simple! Each farm and soil type has different levels of trace elements available to the grass, and elements present in the water may interfere with availability to the animal, for example high levels of iron in water decrease availability of copper in the diet. Every farm is different, and all the trace elements can be toxic if too much is given. There is no point spending money to give sheep extra selenium if they don’t need it and are not going to grow properly because they have too much! Ask your veterinarian, and they will help you develop a preventative animal health plan for your farm and animals.