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How significant is the problem of subclinical milk fever on my farm?

The transition period is the most challenging time during the production cycle of a dairy cow. One of the main factors in determining whether or not a cow transitions efficiently being her ability to maintain normal blood calcium concentrations around calving.

22-10-2020, updated on 07-01-2021
prevent subclinical milk fever

Calcium is the cornerstone of successful dairy cow transition

Calcium is essential for the maintenance of normal function of almost all cells, including those of the immune system. Without adequate calcium, cows and first lactation heifers are at risk of becoming hypocalcemic (calcium deficient) and at increased risk to infections and diseases because immune cell activity is impaired.

The metabolic and physiological demands for calcium increase dramatically as calving approaches: the calving process, colostrum production and milk synthesis imply a requirement for calcium, that may exceed the amount of calcium readily available in the cow’s system – thereby leading to either subclinical or clinical milk fever.

A recent study reported that more than 40% of cows and 14% of first lactation heifers experience post-calving blood calcium concentrations below 8.4 mg/dL. (Venjakob et al. 2017). These subclinical hypocalcemic animals are at greater risk of developing metabolic and infectious diseases postpartum, therefore illustrating the importance of calcium status during the transition period.

Fortunately, the incidence of hypocalcemia can be reduced via the use of adequate nutritional strategies.

Monitoring blood calcium levels

Blood calcium concentrations begin to fall several hours prior to calving due to the onset of colostrum production. During this time, dry matter intake is normally low, thereby exacerbating the problem. Blood calcium concentrations will continue to drop postpartum, with levels at their lowest 12 to 24 h after calving. Cows suffering from calcium deficiency typically won’t fully recover until two to three days after calving when blood calcium concentrations should return to a normal range of 8.5 to 10 mg/dL.

To understand how significant the problem of subclinical milk fever is on your farm work closely with your farm vet to develop a protocol for blood sampling of freshly calved cows: blood samples must be taken from multiparous cows, ideally 48 hours post-calving (sampling window: 36 to 60 hours post-partum) with at least 15 cows being tested in order to give a truly representative overview of the incidence of subclinical hypocalcemia within the herd.

Blood calcium values should be at or above 8.5 mg/dL, with anything below this indicative of an underlying problem.

Meeting the demand for calcium

Hypocalcemia may be prevented through a number of strategies, all of which are designed to maintain the optimum blood calcium concentration. The most practical and effective approaches are based on the ability to manipulate the intake of dietary macro-mineral ions such as chloride, sulphur, sodium and potassium. By feeding a ration with a high content of negative ions (chlorine and sulphur) and lower inclusion of positive ions (sodium and potassium), the cow’s blood becomes mildly acidic. This stimulates the physiological processes needed to mobilise stores of bone calcium and to initiate the uptake of dietary intestinal calcium, both of which are necessary for meeting the calcium demands associated with calving. This strategy is referred to as feeding a negative dietary cation-anion difference (DCAD) ration.


Animate: the key to milk fever prevention

Animate is a thoroughly researched and field-tested product: it is a concentrated and highly palatable anionic mineral product for dry cow rations which, when added to the dry cow ration three weeks prior to calving, can help to optimise calcium metabolism around calving. In doing so, Animate helps to reduce the incidence of clinical and subclinical hypocalcemia, which may help reduce the incidence of metabolic and non-metabolic disorders associated with hypocalcemia.

By preventing the onset of these dairy cow diseases, Animate enables herd managers to improve the performance of their dairy cows during the transition period, and can also result in improved milk yields during the ensuing lactation.


Get a free transition assessment

To find out more about how Animate could help you to optimize your herd’s performance, please contact us to request a callback. We’ll call you within three working days to set a date for a telephone or face-to-face meeting to discuss the following:

  1. Current situation analysis: we’ll work with you to understand your herd’s current status and to identify areas for improvement.
  2. Designing a milk fever prevention protocol: we’ll recommend where improvements can be made and how Animate can unlock your herd’s full potential.
  3. Evaluation: we’ll carry out a detailed review to make sure the changes we’ve put in place are working effectively and, where necessary, provide additional support and advice to enable your herd to continue to improve.
Arnout Dekker
Arnout Dekker
Arnout Dekker is the Marketing Manager Europe of Phibro and has 7 years experience as a veterinarian. He is passionate about cows, dairy farm advisory and farm management. Helping farmers with advice and proven products to keep their cows healthy, produce better, be more profitable and sustainable is what drives and motivates him.

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