20/05/2026
Why do we recommend blood testing at dry off? 🩸🐄
Dry off is more than just the end of the milking season — it’s a great opportunity to check how your cows are tracking before they head into calving.
We often talk to farmers about trace elements such as selenium, iodine, and copper. These minerals play an important role in immunity, fertility, calf health, and milk production, but deficiencies are not always obvious just by looking at the cows.
That’s where testing comes in.
🩸 Blood samples give us a snapshot of what is circulating in the body at the time. In our area, we commonly monitor:
- Selenium
- Iodine
- Magnesium
- GGT (a liver enzyme that can help identify liver damage after a facial eczema season)
🧪 Liver samples are especially useful for checking copper levels. Copper is stored in the liver, so blood levels can sometimes look normal even when overall stores are running low.
Depending on your herd and history, liver samples can also be used to assess selenium, zinc, and vitamin B12.
Why bother testing?
Every farm is different. Some herds need additional supplementation, while others are already well covered. Testing allows us to make informed recommendations based on what your cows actually need, rather than relying on guesswork.
By checking trace elements at dry off, we can:
- Pick up hidden deficiencies
- Fine-tune your supplementation plan
- Avoid unnecessary treatments
- Help set your herd up for a healthier calving and mating season
In our region, selenium and iodine deficiencies are common, so regular monitoring is a simple way to make sure your herd is on the right track.
If you’d like to include trace element testing as part of your dry-off programme this season, get in touch with us!
