However, clinical cases of the disease only represent the tip of the iceberg, and the prevalence of sub-clinical hypocalcaemia is easily overlooked and can therefore be seen as the "hidden" form of the disease. Research from the USDA (2005) has shown that where incidences of clinical hypocalcaemia were present in 6–8% of the herd, there were 60–75% of animals suffering from sub-clinical hypocalcaemia within the herd.

This highlights that high levels of sub-clinical hypocalcaemia can occur in herds showing only few clinical cases of milk fever. Recent studies of blood calcium by lactation number confirms the high prevalence of sub-clinical hypocalcaemia whilst also highlighting the occurrence of the disease in 1st and 2nd lactation animals. Sub-clinical hypocalcaemia has been proven to result in production losses, reduced fertility and incidence of other diseases.

Massey et al. (1993) found that cows with sub-clinical hypocalcaemia were 4.8 times more likely to have left displaced abomasums, regardless of whether they developed clinical signs of milk fever. Because sub-clinical hypocalcaemia is often untreated, it is possible that it has a greater impact on the profitability of dairy farmers than clinical milk fever.

Calcium deficiency leads to secondary disorders

Studies have also shown that hypocalcaemia is the initiator in increasing incidence of other metabolic and infectious disorders which have a huge impact of performance and profitability on dairy units. Hypocalcaemia reduces muscle function and immune response and as a result this leads to a knock-on effect to other disorders:

  • Muscle function
  • Immune function
  • Mastitis
  • Teat sphincter contraction
  • Rumen fill
  • Feed intake
  • Calving difficulties
  • Uterine motility
  • Rumen and GIT motility
  • Retained cleansing
  • Reproduction
  • Fatty liver
  • Ketosis
  • Energy balance
  • Milk yield
  • Displaced abomasums (LDA)
  • Uterine involution
  • Culling/Death
  • Loss of income
  • Reproduction
  • Metritis

Animals suffering from hypocalcaemia have a significantly increased risk of other diseases:

  • 9-fold increase in the incidence of ketosis
  • 6 times more dystocia/calving difficulties
  • 4-fold increase in the incidence of left displaced abomasums
  • 4 times more cases of retained placenta

In addition, the majority of infectious diseases such as mastitis, salmonellosis etc. are associated or increased by hypocalcaemia. X-Zelit® contains synthetic zeolite, a substance which is effective in binding calcium in the contents of the gastro-intestinal tract. The addition of zeolite to the animal's diet in the two weeks prior to calving binds the calcium that is supplied from the feed, which reduces the quantity of available calcium.

In turn, this causes hormones to adjust to a condition of low calcium availability. The cow's own hormone system is therefore stimulated, which results in effective mobilisation and absorption of calcium from its own body reserves. This boosts the cow's blood calcium content around calving and it strengthens the cow's ability to utilise the body's calcium resources. At calving X-Zelit® is withdrawn from the diet and the cow also has access to dietary calcium as well as calcium from body reserves. The result is a stable blood calcium content which reduces the risk of milk fever and better equips the cow for future milk production and possible future calving.

The provision of zeolite can prevent hypocalcaemia (clinical and sub-clinical), but above all it safeguards the health of the cow by stimulating its natural systems to regulate the calcium content of the blood during calving. Prior Preparation Provides Stability In order to meet the increased demand for calcium after calving, the cow's hormone system needs to adjust from a state of passive absorption to active absorption of calcium from the body reserves (from the small intestines and the bones). A considerable increase of absorption from the small intestine requires 24 hours' stimulation, and from the skeleton requires 48 hours.

This stimulation period results in a depletion of blood calcium before calcium can be made available from the body. X-Zelit®'s mode of action stimulates active absorption prior to the increased demand, so the cow is prepared for stable milk production. This article looks closely at this contentious issue. Learn about how companies like VITFOSS are bringing innovation to the problem to help reduce losses and improve health.