Milk fever from a shortage of calcium is more common in dairy cows. However low calcium blood levels also reduce muscle tone and lead to “slow calvings” and all its associated problems.
The risk of both clinical and subclinical hypocalcaemia can be higher in the summer months.
Results from a three year trial run by James Husband at EBVC suggested that 57% of dairy cows were experiencing hypocalcemia post calving.
- A large proportion of these were subclinical cases, only detected by blood sampling.
- Sub clinical hypocalcaemia is a significant risk factor for retained foetal membranes, metritis and endometritis.
- The only way to know if subclinical milk fever is an issue is to blood sample fresh calved cows within 24 hours of calving.
- If blood calcium levels are below 2 mmol/litre in the first 24 hours after calving then subclinical milk fever is occurring.
If you have slow calving cows ask your vet to take a blood sample from a few recently calved animals. Also make sure magnesium supplements are available to dry cows to help improve blood calcium levels and muscle tone.
Heather Stevenson, email@example.com
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