A recumbent crossbred cow after calving: calcium, differential diagnosis and prevention
A farmer in Kamrup has two crossbred (HF × local) cows. The older cow, in her third lactation, calved four days ago and is giving 14 litres/day. She has suddenly become recumbent, with cold ears, muscle tremors and a stiff, unsteady gait; temperature is 37.8°C, rumen movements are 2 per minute, and she refuses concentrate but drinks water. The farmer has calcium borogluconate injection and wants to give it himself. The second cow is due to calve in three weeks; she is on a diet of 8 kg paddy straw, 3 kg crushed rice and 1 kg mustard cake, with no mineral mixture.
1. What is the likely condition? Justify your answer from the signs and stage of lactation. What immediate action is appropriate, and what should the farmer not do?
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Likely condition. The signs point to hypocalcaemia, commonly called milk fever. The cow calved four days ago, is a high-yielding crossbred, and has become recumbent with cold ears, tremors, a subnormal temperature of 37.8°C and sluggish rumen movements. The absence of fever argues against an acute infection, and the sudden onset after calving fits the classic pattern. Differential diagnoses include ketosis, hypomagnesaemia, toxic mastitis, metritis and displaced abomasum; ketosis often has a ketone smell and occurs later, while hypomagnesaemia tends to cause excitability and tetany.
Immediate action. Call a veterinarian. Keep the cow in sternal recumbency on a dry, well-bedded area, provide warmth, and offer water. Calcium borogluconate is the specific treatment, but it should be given slowly intravenously by a veterinarian while monitoring the heart rate; too rapid an injection can cause bradycardia and dangerous arrhythmias. If intravenous access is not possible, the veterinarian may use a divided subcutaneous route, but that is a professional decision.
What not to do. Do not give a rapid intravenous bolus yourself, do not force feed an unresponsive cow, and do not assume that every recumbent cow needs calcium without checking for mastitis, metritis or ketosis. The farmer should not use the bottle blindly without veterinary guidance.
2. Design a prevention plan for the second cow due in three weeks, using the existing ration as a starting point. Include feeding, mineral strategy and what you would monitor.
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Ration review. The current diet is 8 kg paddy straw, 3 kg crushed rice and 1 kg mustard cake. It is low in calcium, low in green fodder and unbalanced in minerals, and the crushed rice adds energy without adding calcium. Paddy straw is also poor-quality roughage. Before calving, transition gradually to a better ration: add 5-8 kg of green fodder such as hybrid napier or legume fodder, provide a balanced mineral mixture at about 50 g per day, and give 30-50 g of common salt. Avoid sudden changes and avoid overfeeding the dry cow, because obesity increases calving problems.
Calcium strategy. Do not load the pre-calving diet with excess calcium; the objective is a balanced transition ration with adequate but not excessive calcium and a correct Ca:P ratio. The mineral mixture should supply calcium, phosphorus, magnesium and trace minerals. After calving, monitor appetite and rumen motility and discuss with the veterinarian whether an oral calcium supplement is appropriate for this cow, given her herd history.
Monitoring. Record feed intake, temperature, rumen movements, demeanour and milk yield daily around calving. Check for retained placenta and mastitis. Body condition should be assessed before calving. These records will show whether the prevention plan is working and will help the veterinarian decide whether specific treatment is needed.