What can I do to prevent milk fever on my dairy farm this year?

Dairy farmers are being reminded of the important role of dry cow management, in particular nutrition and mineral supplementation, when looking to the future in terms of health and productivity.

With calving just around the corner on many dairy farms, there are many minerals that are important to the dairy cow.

One disease that farmers will all be familiar with is milk fever. As a result of milk fever, cows often ‘go down’ after calving from low levels of blood calcium (Ca).

In the majority of cases, cows will recover; however, if the problem is not addressed early it can result in death. In addition, it is not unusual for these cows to get mastitis or other infections even after Ca has been administered.

Speaking to AgriLand, Padraig Hennessy from Terra NutriTECH explained the importance of mineral supplementation to prevent milk fever.

He said: “When a cow starts producing colostrum two weeks out from calving – and particularly when she starts to milk – she has a huge requirement for Ca.

“So, it would seem simple; a cow coming up to calving needs more Ca. However, this is where Ca can confuse farmers and get a little more complicated.

A cow has a complicated Ca metabolism that is heavily influenced by some other macro minerals and even her body condition score.

“The cow cannot consume enough Ca around calving to meet her demands, so she pulls over 90% of her Ca requirements from her bones; this allows the freshly calved cow to meet demands while adjusting her dietary intake to bridge the gap.”

One of the most important minerals in this process is magnesium (Mg). Padraig also highlighted that correct levels of blood Mg actually send a signal through a complex pathway to tell the cow she needs to pull Ca from the bone.

This is why Mg is such an important mineral in the weeks leading up to calving.

This can be further influenced by potassium (K) which actually binds up Mg leading to more risk of low blood Ca or milk fever; K itself is actually antagonistic to Mg.

In Ireland, we feed silage during the dry period. So generally, what we see in grass silage is higher levels of K and that’s related to the slurry and fertilisers that are applied; therefore, minerals need to be managed correctly.

“By managing Ca and the minerals that interact with it around calving, you can make a big impact on reducing the risk of diseases like uterine infections, mastitis and even displaced stomachs,” he concluded.