The Importance of Calcium in Cows – Animal Health.

January 13, 2020

There are many minerals that are important to the dairy cow. We split these minerals into (macro) larger minerals and (micro) trace elements. The most important of them is calcium a macromineral that around calving time is crucial to be managed correctly. 

Farmers will all be familiar with the term milk fever, where cows often after calving can go down from low levels of blood calcium. This if not addressed fairly quickly can lead to lots of problems even death. while most cases recover, it is all the knock-on challenges of a cow being down and recovering from injuries bruising etc. It is not unusual for these cows to get mastitis or other infections even after calcium’s administered.  

The problem in our herds is this might only be the tip of the iceberg. Many cows can have low blood calcium without being down. This can be a big problem on your dairy farms if not addressed. We advise and aim for milk fever incidences in the herds we work with below 1%. 

Can a cow low in calcium have health problems? 

Calcium plays a role in many organs but the big roles are muscle function and immunity. So this is why in severe cases we get cows down due to muscle weakness with milk fever. If calcium isn’t administered then the cows’ heart muscle can fail. In cows with low levels of calcium, you can get immunity issues, mastitis and wombs infections. 

Why calcium in Cow is so important? 

When a cow starts producing colostrum 2 weeks out from calving and particularly when she starts to milk she has a huge requirement for calcium (milk is packed with calcium). So it would seem simple a cow coming up to calving needs more calcium? 

This is where calcium can confuse people and get a little more complicated. A cow has a complicated calcium metabolism that is heavily influenced by some other macro minerals and even her BCS can affect it. 

The cow cannot consume enough calcium around calving to meet her demands so she pulls over 90% of her calcium 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.

How it links with Magnesium

Proper levels of blood Magnesium actually sends a signal through a complex pathway to tell the cow she needs to pull calcium from the bone. This is why magnesium is such an important mineral in the weeks leading up to calving. This can be further influenced by potassium which actually binds up magnesium leading to more risk of low blood calcium or milk fever. This is a particular risk in the Irish system due to slurry application (high in potassium) to silage ground. Again, over the years we have seen these minerals at different levels in Irish farms. With our system, we encourage farmers to look at their silage mineral analysis and look at risk factors early.  

This information when addressed early can feed into the levels of magnesium your herd may require before calving. Our system allows daily requirements to be delivered and increased where the risk or clinical issues like milk fever arise. By managing calcium 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. 

Talk to us today about how we can uniquely manage calcium in your herd for more profit and healthier cows.