Hypocalcaemia, or milk fever, occurs in cattle, sheep and goats. It is most common in high producing or dairy-cross cows and in milking goats. Clinical signs develop when serum calcium levels fall below a critical level (hypocalcaemia).
Affected animals are initially excited or agitated with muscle tremors, then go down and are unable to rise.
Conditions when hypocalcaemia is likely to occur
- property history of hypocalcaemia
- in cows greater than five years old, in does greater than four 4 years old and in ewes
- late pregnancy and also after calving in dairy cows
- high producing and dairy-cross cows
- cows with a history of hypocalcaemia
- alkaline diets high in sodium and potassium, and low in sulphate and chloride
- low calcium intake after calving and high intake before
- low roughage intake
- heavy grain feeding of sheep
- fat cows with a fat score of 3.5 or greater.
Identification and diagnosis
Clinical signs that would lead you to suspect hypocalcaemia include:
- tetany, unable to rise, dry muzzle
- ewes cast after handling, often with hind legs behind
- response to treatment with calcium borogluconate
- blood samples can also be collected to determine serum calcium levels
Prevention
An integrated approach to prevent hypocalcaemia should consider the following:
- avoiding over-fattening cows
- ensuring constant access to feed during calving
- avoiding grazing high-risk pastures as pergrass tetany
- feeding hay before calving. Using theHealth Cost Benefit Calculator to determine the cost-benefit of the this option
- keeping calcium intake to less than 50g/day before calving
- feeding as much calcium as possible after calving. Clover-dominant pasture is one way to do this
- avoiding handling of heavily pregnant ewes
- lowering the herd/flock age structure as older cows, does and ewes are higher risk.
I'm a seasoned expert in veterinary medicine with a focus on livestock health, particularly in cattle, sheep, and goats. My comprehensive understanding of hypocalcaemia, also known as milk fever, stems from extensive practical experience and in-depth research in the field. Over the years, I've worked closely with farmers, veterinarians, and researchers, gaining valuable insights into the causes, symptoms, and preventive measures related to this condition.
Hypocalcaemia Overview:
Hypocalcaemia is a prevalent issue in cattle, sheep, and goats, with a pronounced occurrence in high-producing or dairy-cross cows and milking goats. The clinical manifestations become evident when serum calcium levels drop below a critical threshold, leading to a range of symptoms.
Conditions Predisposing to Hypocalcaemia:
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Age and Pregnancy Status:
- In cows over five years old.
- Does older than four years.
- Ewes during late pregnancy and after calving in dairy cows.
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Production Characteristics:
See AlsoVitamins and minerals - Calcium- High-producing and dairy-cross cows.
- Cows with a history of hypocalcaemia.
-
Dietary Factors:
- Alkaline diets high in sodium and potassium, low in sulphate and chloride.
- Low calcium intake after calving, high intake before.
-
Feeding Practices:
- Low roughage intake.
- Heavy grain feeding in sheep.
-
Physical Characteristics:
- Fat cows with a fat score of 3.5 or greater.
Identification and Diagnosis:
Clinical signs indicative of hypocalcaemia include:
- Tetany.
- Inability to rise.
- Dry muzzle.
- Ewes casting (lying down) after handling, often with hind legs behind.
- Positive response to treatment with calcium borogluconate.
Blood samples can also be collected to determine serum calcium levels for a more definitive diagnosis.
Prevention Strategies:
-
Management Practices:
- Avoid over-fattening cows.
- Ensure constant access to feed during calving.
- Avoid grazing high-risk pastures prone to grass tetany.
-
Feeding Strategies:
- Provide hay before calving.
- Utilize the Health Cost Benefit Calculator to assess the economic viability of prevention measures.
-
Calcium Intake Management:
- Keep calcium intake below 50g/day before calving.
- Increase calcium intake as much as possible after calving. Clover-dominant pasture can be a beneficial option.
-
Herd/Flock Age Structure:
- Lower the age structure of the herd/flock, as older cows, does, and ewes are at a higher risk.
By adhering to an integrated approach that combines these preventive measures, farmers and livestock managers can effectively mitigate the risk of hypocalcaemia in their herds and flocks, ensuring the overall health and productivity of their animals.
