Now is the time to get your minerals right for mating

Now is the time to get your minerals right for mating
Julia Baynes, Veterinarian, Anexa Vets

It may be autumn, but this message is for our Spring farmers. Autumn is the time to assess your herd’s mineral status. You need to ensure that your cows have enough copper and selenium reserves to get them through to calving and mating.

The heifers are also due home, and they will have a different mineral status from the herd. As they head into late pregnancy, it’s important that they have enough copper, selenium and cobalt/B12 for a successful first calving and lactation. We also want to give them every chance for mating – we don’t want them leaving the farm as empty 2-year-olds!

Yearlings are heading into their first winter, and if they are copper, selenium or cobalt/B12 deficient, they won’t grow as well as they should, which will have knock-on effects to their first mating. They are also more susceptible to certain diseases.

That’s why Anexa vets recommend doing trace element testing of yearlings, heifers and cows in the autumn. We want to ensure your herd’s mineral supplementation plan is working: that animals have adequate levels of copper, selenium and cobalt/B12. We want to reduce the risk of them becoming deficient in any of these trace elements in the Spring.

There are three steps to a successful mineral plan:


1. Determine the current mineral supplementation plan

Surprisingly, this is the step that is most often missed. Before testing is completed, it’s important to work out the type and quantity of each mineral that is currently being supplemented to the cows, heifers and yearlings. This mineral history, combined with testing results, will inform us whether the current mineral supplementation is working, or whether it needs to be changed.

Don’t forget your heifers who are returning home from grazing. Their mineral history is often very different to your dairy platform, and they may return home copper or selenium deficient.
Anexa has developed a mineral check form for this purpose, which is included with this newsletter. Do take the time to complete this form for your farm and discuss it with your vet.


2. Test each group of animals for trace elements

In order to test for trace elements, your vet will need to take blood and/or liver samples from a random selection of healthy animals from each age group. Cows, heifers and yearlings should be treated as distinct groups, and if mobs have received different mineral supplementation e.g. two mixed-age herds on the same farm – they should also be tested as separate groups.

The most important trace elements we test for across all age groups are copper and selenium. Both play a vital role in reproduction and general health. Cobalt/B12 is especially important in growing animals, so is routinely tested in yearlings and heifers.

Liver samples are the best for testing copper reserve levels, while blood samples are preferred for selenium and cobalt/B12. Typically, we aim for 10 blood samples per group, and a minimum of 6 liver biopsies, but these numbers vary depending on the mob size.

These samples are then sent to the lab for testing. We are most interested in seeing the average result for each trace element – does the mob have adequate copper reserves, as well as adequate selenium levels? Are these results consistent with the supplementation history?


3. Review the mineral supplementation plan and treat animals if required

Armed with the farm’s current mineral supplementation plan and trace element test results, farmers and vets can work together to:
  • Identify any immediate actions that should be taken e.g. heifers require a bolus as soon as possible as their liver copper reserves aren’t sufficient for winter;
  • Identify any changes to the mineral supplementation plan e.g. add copper to the herd mineral mix for next season, ensure selenium prills go in the spring fertiliser;
  • Identify the next time the herd will be tested to ensure the revised mineral supplementation plan is working.
If you are interested in getting your minerals right for the season ahead, speak to your Anexa Vet and complete a Mineral Check form.

Mineral Checker Form


Date Added: Thursday, 29th April 2021


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