Milk fever or clinical hypocalcemia is a major threat. It can affect up to one cow of ten in dairy herds. Subclinical hypocalcemia, which affects 25% of cows from their first lactation*, is less well-known because not so obvious. However it causes many health problems such as retained placenta, difficult calving, metritis, ketosis, mastitis, reproductive disorders, drop in production, increased culling rate, etc.
*Reinhardt TA et al (Vet J. 2011 Apr;188(1):122-4)