Managing your minerals premating

With mating on the horizon, now is a great time to assess the mineral status of the herd. This is particularly important at this time of year for Autumn herds due to the combination of mating and the naturally decreasing levels of copper in pasture as the weather cools down. Studies have shown that cows supplemented with minerals such as copper and selenium have higher conception rates and reduced incidences of reproductive disorders.

Performing liver biopsies is the most accurate way of assessing mineral stores, especially copper. The liver maintains blood copper at a constant level until there is a clinical deficiency present. Only then would we detect low levels of copper on blood testing. In this instance, we are wanting to check mineral sufficiency, not deficiency.

A liver biopsy is a straightforward, low-risk, surgical procedure that can be performed on farm. Under local anaesthetic, a small scalpel incision is made between the ribs which allows the biopsy trocar to be inserted into the liver and a very small amount of liver tissue is collected. Ideally, 8-10 individuals would be sampled with a mixture of age groups represented.

Once we have received the results of the liver biopsies a mineral supplementation program can be designed specifically for your herd. Supplementation of cows in the milking herd usually consists of injectable products that rapidly increase mineral levels over a short period of time. 

Multimin is a trace mineral supplementation containing Copper, Selenium, Manganese, and Zinc. Studies have shown that cows that received supplementation with Multimin 4 weeks prior to mating had, on average, 3.3% increased in-calf rates and got in calf 3.4 day earlier compared to cows that didn’t receive supplementation.

Don’t forget to also supplement your young stock during this time as they too often require additional minerals to get them through the winter. This will help keep their growth rate up assisting them with meeting growth targets.

If you would like to know more about mineral testing or supplementation, please get in contact with your regular Franklin Vets clinic.

Neil Murray B.VSc