Understanding the causes of Milk Fever and the symptoms - UFAC UK
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Milk fever is preventable in high-performing dairy cows by adapting the diet to ensure optimal calcium levels in the bloodstream.

Whilst many people assume that metal in the body is highly toxic, some of these metals, such as iron and zinc are crucial in allowing vital chemicals to be transported around the body. 

Calcium is one of these metal components that is extremely important for high producing dairy coas to maintain. A cow needs just 3-4g of calcium in her blood and around 9g of calcium in her muscle tissue fluids to maintain muscle strength. A similar amount of calcium is also kept in her bones to be accessed quickly if these levels drop within her blood. 

During the calving period, the cow will provide calcium to her calf, with colostrum containing around 2g of calcium per litre. This means that when a cow is calving, her blood calcium levels are reduced several times over depending on how much colostrum she makes. This drastic reduction in calcium in the cow could result in milk fever.

What is milk fever? 

Milk fever, known as hypocalcaemia, is a disorder seen in high producing dairy cows just after or before calving. Milk fever occurs when calcium levels in the blood are too low to meet the requirement for milk production at that time. 

The disorder could potentially result in dystocia, stillborn calves and even death in severe cases. The majority of milk fever cases in cows occur within 24 hours of calving and affect between 3 and 8% of dairy cows that are close to calving, or lactating cows shortly after calving.

Causes of milk fever

Most cases of milk fever occur due to the cow’s demand for calcium increasing significantly as she gets closer to calving. High levels of colostrum and milk production are needed during the post-calving period. This means that a high amount of calcium will be taken from the blood. If the cow is unable to replace the calcium in the blood from existing reserves in her bones, she could suffer from a deficiency.

Symptoms to look out for

An important part of preventing milk fever in your herd will be knowing what symptoms to look out for. Milk fever in cows can be predicted by observing the following signs and paying extra attention to the cow after the calving period. 

Symptoms of milk fever include;

  • Loss of appetite
  • Nervousness
  • Weight shifting
  • Hypersensitivity
  • Hind feet shuffling
  • Dry muzzle
  • Cold ears
  • Muscle tremors
  • Progressive loss of consciousness
  • Coma

How to prevent milk fever 

Now that you are aware of the symptoms to look out for, it is also important to be aware of ways to prevent the disorder. Milk fever is preventable by adapting the diet to ensure optimal calcium levels in the bloodstream.

It is recommended that farmers monitor the cow’s feed and test the mineral content of the forage regularly. Balancing the feed is vital in ensuring that the right amount of each mineral is being ingested by the cow. 

Formulating the ration to contain a low potassium content is recommended as well as supplementing vitamin D for better calcium absorption. In high producing dairy cows, some nutritionists will perhaps suggest the use of anionic salts in the period just before calving to acidify the rumen and ensure optimal calcium absorption.

It is important to avoid feeds that are high in calcium during the dry period and use as many palatable ingredients as possible. With cows that have a history of contracting milk fever, it is also important to consider administering calcium injections. 

Fill out the form below to find out how UFAC products can help maintain overall herd health or contact our Regional Business Managers directly.


Mark Townsend 

M: 07788 294 539

South West and Wales 


Richard Lapthorne 

M: 07788 963 487

North England and Scotland 


James Hastings-Molyneux 

M: 07538 763 832

South East and Mildlands