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Sources
- Soil, leaves and stems of plants , bones, shells
Functions
- Ossification of bones and calcification of cartilage
- Body fluids , activating several hydrolytic enzymes
- Nerve cell excitation
- Calcium metabolism is under the control of vit. D, parathyroid hormone, calcitonin
- Milk production, egg laying and reproduction
- Normal Ca level in blood = 10-11mg /100 ml blood
- 8mg % in tetany
- 6 mg % in tetany, paralysis, coma, death
Causes for deficiency
- ↓ dietary intake
- Malabsorption
- vit. D deficiency
- ↑ excretion from kidneys
- Parathyroid deficiency
- Formation of insoluble complexes
Deficiency diseases
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Osteomalacia
- Softening of bones esp. during pregnancy
- Fractures, distortion, bowing of legs
- Abnormal curvature of back
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- Rapid depletion of calcium from the blood at the beginning of lactation
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Clinical signs
- Tetany, incoordination
- Muscular spasms
- Unconsciousness, death
- The animal lies with head turned towards the flank
- Seen in heavy milking cows with ↓ calcium in diet
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Poultry
- Rickets, Osteomalacia → Osteoporosis in laying hens. Thin shelled eggs
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Cage layer fatigue
- Seen in caged hens – sudden paralysis with legs extended
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Excess of calcium
- Normal blood - Ca: P is present in 2:1 ratio
- ↑ Ca in diet, ↑ vit. D → Hypercalcemia
Metastatic calcification
↑ blood Ca level
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Causes
- ↑ Ca, ↑ vit.D, tumours of parathyroid gland
- Tumours of bones
- Renal disease – reabsorption of P → ↑ P
- ↓Ca → ↑ Ca withdrawal
- Lungs - alveoli calcified
- Stomach - Mucus membrane calcified
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Dystrophic calcification
- Calcium level of blood is normal
- Calcium deposited in dead tissues
- Caseous tuberculosis, walls of atheromatous blood vessels, abscess, tumours, parasites,
- Thrombi, actinomycosis, scars, necrotic areas
- Poultry
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