Page 18 - Dairy Dimension - July Aug 25

| Volume 1 | Issue 5 | July-Agu 2025 ARTICLE
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Calcium Homeostasis in
Post-Parturient Dairy Cows:
Implications for Health, Productivity,
and Metabolic Resilience
by Dr. Pawar Rutik Namdev & Dr. Shipra Tiwari, MVSc. Scholar, Department of
Livestock Products Technology, College of Veterinary Science and Animal Husbandry, DUVASU Mathura
Abstract
Calcium metabolism during the periparturient period
plays a crucial role in the health and productivity of dairy
cows. The sudden surge in calcium demand for
colostrum and milk synthesis immediately after calving
often exceeds the body's homeostatic capacity,
predisposing cows to both clinical and subclinical
hypocalcemia. These disorders not only compromise
animal health but also negatively impact fertility, milk
production, and overall farm profitability. This review
examines the physiological basis of calcium dynamics in
post-parturient dairy cows, assesses the consequences
Dr. Pawar Rutik Namdev of impaired regulation, and discusses practical strategies
for its prevention and management. A thorough
understanding of these mechanisms is essential for
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| Volume 1 | Issue 5 | July-Agu 2025
enhances intestinal absorption of dietary calcium.
· Calcitonin: Secreted from the thyroid gland, calcitonin
counteracts PTH by inhibiting bone resorption during
calcium excess.
In the immediate postpartum period, the outflow of
calcium into milk can exceed 30–40 g/day, placing
immense stress on these homeostatic systems. The
speed and efficiency with which cows adapt determines
whether they remain normocalcemic or develop clinical
or subclinical hypocalcemia.
Factors influencing hypocalcemia risk include:
· Parity: Multiparous cows are at greater risk due to
Dr. Shipra Tiwari reduced bone resorption efficiency.
maintaining the productivity and welfare of high-yielding · Breed: Jersey cows are more susceptible compared
dairy herds. to Holsteins.
Introduction · Diet: High dietary cation-anion difference (DCAD)
Calcium (Ca) is a vital macromineral involved in diets predispose cows to hypocalcemia, while
numerous physiological processes, including bone controlled prepartum calcium intake enhances
formation, nerve conduction, muscle contraction, and · adaptation.
blood clotting. In dairy cows, calcium becomes especially
Genetics: Genetic predisposition to milk fever has
critical during the periparturient period due to the been documented, with heritability estimates being
sudden onset of lactation. The abrupt increase in
low but significant.
calcium demand for colostrum and milk synthesis often Environmental Stressors: Heat stress, overcrowding,
exceeds the body's immediate capacity for mobilization · and poor transition cow management exacerbate the
and absorption, leading to hypocalcemia. risk.
Post-parturient hypocalcemia, commonly referred to as Globally, the prevalence of clinical hypocalcemia ranges
“milk fever,” has long been recognized as a disorder
affecting high-yielding cows. However, recent research from 3% to 10%, while subclinical hypocalcemia may
affect up to 50% of multiparous cows in early lactation.
suggests that subclinical hypocalcemia—though not
visibly apparent—may be far more prevalent and equally Clinical and Subclinical Hypocalcemia:
detrimental. Its hidden impacts on feed intake, immune Differentiating Impacts
function, and reproductive performance underscore the · Clinical Hypocalcemia (Milk Fever): Characterized
need for a deeper understanding of calcium dynamics to by recumbency, muscle weakness, cold extremities,
design effective preventive strategies. and potentially coma if left untreated. Immediate
Physiology of Calcium Homeostasis intravenous calcium therapy is required.
Calcium homeostasis in dairy cows is tightly regulated · Subclinical Hypocalcemia (SCH): Defined as blood
through a complex interplay of hormones and tissues. calcium <2.0 mmol/L without obvious clinical signs.
The key regulatory mechanisms include: SCH leads to immunosuppression, reduced dry
matter intake, and increased risk of secondary
· Parathyroid Hormone (PTH): Secreted in response to
declining blood calcium, PTH stimulates bone disorders such as ketosis, displaced abomasum,
resorption, enhances renal calcium reabsorption, and mastitis, and impaired fertility.
increases synthesis of active vitamin D. While clinical cases are more visible, SCH imposes a far
· 1,25-Dihydroxyvitamin D (Calcitriol): Produced in the greater hidden economic burden by reducing herd
kidneys under the influence of PTH, calcitriol productivity and longevity.
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