Copper Complacency

Over the last 10-12 years a level of complacency has developed around copper deficiency and the need to supplement. This has come about largely through the feeding of palm kernel. PKE has been a great supplementary feed source and it has the bonus of being high in the trace element copper.

However, the replacement R1’s & R2’s are away from the milking platform where they are fed a mostly pasture or crop-based diet depending on the season. Replacements, therefore, are at far higher risk of developing Cu deficiency than a milking herd being fed PKE through the season.

The extent of this problem was investigated several years ago when our practice conducted some basic surveillance work looking at copper levels in rising two-year-olds at grazing. We found that over 80% of R2 mobs sampled had individual animals deficient in copper.

Before disregarding the need to supplement copper in R1’s and R2’s consider the following points:

• Copper levels are at their lowest in late winter/early spring. This coincides with higher copper demands over this period for late pregnancy and early lactation.

• First calving heifers are often slow to start eating PKE in the shed unless they have been fed it as calves. So, feeding PKE can be an unreliable way of supplementing copper to these animals.

• Humeral fractures are a major issue on individual farms and a significant animal welfare problem. While copper supplementation is not the silver bullet to stopping their occurrence it is a key part of the prevention strategy.

The optimal time to supplement Copper in R1’s and R2’s is mid-late autumn before animals go onto winter crop.

Options to supplement Copper in R1’s and R2’s:

• Coppermax and Copaject injection. This can be safely given to cattle over 4 months of age. A 2ml dose is given under the skin of the neck. The dosage may be increased up to a maximum of 4ml if severe copper deficiency has been confirmed through liver biopsies.

• Copper bullets. These are given orally and contain copper oxide wire particles in gelatine capsules. Typically, a R1 would be given a 10 or 20g capsule and a R2 a 30 or 36g capsule depending on liveweight.

To establish the true copper status of a milking herd 5 liver biopsies are the way to go and we should never assume the copper status of a dairy herd is fine because PKE has been fed during the season. Copper levels will naturally decrease over winter especially if the herd is wintered on crop and the property has no in-line dispenser in the water system.

Whilst blood samples can measure copper levels easily, this only tells us what an animal’s copper status is on an individual day. It unfortunately tells us nothing about the animals’ copper stores in the liver which is of far greater importance going into winter.

Liver biopsies are quickly and easily performed on farm. Whilst collecting liver samples from cull cows at the freezing works is convenient on farm liver biopsies have several advantages.

• The vet is on farm so can select the animals to be biopsied.

• Accurate animal identification at sampling.

• Clear traceability of samples from collection to reporting.