Milk fever and Downer cows
Incidence of milk fever (or hypocalcaemia) may vary from 3% to as high as 30% in some herds.
Estimated profit loss from lost production, death loss, and veterinary costs associated with clinical
cases of milk fever range as high as $225 for each episode. The losses from subclinical milk fever may
be substantial but are more difficult to measure.
Milk fever is not a disease but only the clinical expression of a mineral imbalance at a period of
physiological stress. While the final expression of milk fever is caused by low blood calcium, a
predisposing cause can be either low phosphorus in the ration or sources of phosphorus that are
relatively unavailable.
It may also be noted, that about half of all hypocalcaemic cows have subnormal levels of blood
phosphate, which may complicate the treatment of these cases.
Low phosphorus intake can occur in case of diets with high forage and low grain. Like pasturing dry
cows (only eating grass) for instance.
Disturbances in phosphorus metabolism can occur secondary to disturbances in the calcium
metabolism.
Too low phosphorus levels in the blood may lead to Downer Cow Syndrome.
Milk fever cows with a phosphorus level of ≥ 0.9 mmol/L are 12 times more likely not to become a
Downer Cow than the ones with a phosphorus level < 0.9 mmol/L in the blood.
It is common that the herd as a handful of cows that always develop milk fever after calving. In this
situation it is advisable that one supplements using an oral treatment of calcium. Where it is
suspected that the cow has also low blood phosphate levels, a supplement that contains calcium and
phosphorus is advised. Both of such products can easily be used with infused Calcium borogluconate
(Bottle of Calcium).
A good option is 1 Calcitop bolus + 1 Fosfotop bolus together.
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