Copper and selenium: now is the time to re-test!

Copper and selenium: now is the time to re-test!
By Julia Baynes, Veterinarian, Anexa Vets Morrinsville

Don’t assume that injecting your animals with copper will cover your bases. Injecting with copper close to mating is NOT recommended due to negative impacts on fertility.

Now is the time to ensure your trace element supplementation programme is up to scratch to enable a successful mating period in the coming months. The most important trace elements in dairy cattle are copper, selenium and cobalt/B12.

For those of you who did trace element testing in autumn, you would have put plans in place to ensure your animals didn’t become deficient over the winter period. However, it’s important to check that your plan is working, as things may have changed since June, such as:
  • You have fed less (nil PKE) since calving because you’ve had loads of grass;
  • The dosatron wasn’t working for ages;
  • Late calvers left the milking platform and there is no trace mineral supplementation on that block;
  • You have changed your mind and decided not to put the trace mineral pellet in the meal mix.
Copper and selenium are critical for cows to return to cycling, show good heats, and hold their pregnancy. Late winter and spring are the seasons when copper and selenium levels are lowest in the pasture, and arguably the most critical to your herd.

Sometimes, there are signs that your animals are deficient in important trace elements. For example, if you have had a higher number of retained fetal membranes (RFMs) or dirty cows than usual, this can be linked with trace mineral deficiencies. Unfortunately, sometimes there are no obvious outward signs of deficiency – except for a poorer reproductive performance or reduced production.

That’s why testing is so important. Blood testing and liver biopsies can be performed to check copper and selenium levels in adult cows. Both tests will give you valuable information about the trace element status of your herd. Metrichecking is an ideal time for your vet to take these samples.

And don’t forget your replacement heifers! Copper, selenium and cobalt/B12 are not only required for reproduction, but also for growth. It’s critical to ensure your heifers have adequate trace element levels to set them up well for their first mating and ultimately, their life in the milking herd.
Speak to your Anexa vet about trace element testing for your herd and replacement heifers, well before mating gets underway.

Date Added: Thursday, 3rd September 2020