Two key elements to consider prior to mating and before winter are selenium and iodine.

Selenium plays a vital role in immune function, fertility, and lamb viability. Southland, as we know, has very deficient soils, meaning pasture alone usually does not meet requirements.

You can check your stock’s selenium status with a blood test measuring glutathione peroxidase (GPx). This reflects selenium intake over the previous few months.

• GPx levels <4 - indicate deficiency and ewes should receive additional selenium supplementation.

• GPx levels >10 - ideal for good fertility and adequate selenium intake through pregnancy and over winter.

Selenium supplementation options include long-acting selenium injections, short-acting selenium injections and prills.

If you have not tested your ewes in the last 12 months, then any time now is a good time to check their levels. Give us a call to book in, or consider signing up to our OviGold programme to get this covered each year. We can even do them on your trailer if you’d prefer to bring some sheep to the clinic.

Iodine is also important for reproductive performance and lamb development, by supporting thyroid hormone production. Iodine deficiency in ewes can contribute to poor lamb survival, i.e. weaker and smaller lambs and increased lamb death post-birth.

Ewes on crop over winter tend to have lower iodine intake. Ewes on brassicas, e.g. kale or specific clovers, can also get secondary iodine deficiency as these crops produce goitrogens that inhibit the uptake of iodine.

Iodine supplementation options include the long-acting injectable Depodine/ Flexidine and oral drenches, such as RPM pre-tup and 8 weeks and 4 weeks pre-lamb.

If you want to chat about your farm-specific situation, or have any questions about trace elements for your stock, give your KeyVet a call.