Mastitis Outbreak and Antibiotic Milk in a Dairy Unit
A dairy unit in Ahmednagar keeps 12 crossbred cows (HF × Gir) in a loose house. Average yield is 14 L/cow/day. The feeder uses a total mixed ration of maize silage, lucerne hay and concentrate, and milks by hand twice daily. Over 5 days, two cows show a 35% drop in milk, flakes and clots in the strip cup, and a hot, swollen left hind quarter. The milk from these cows is still being pooled with the bulk tank. The worker dips teats only after milking and uses a single cloth to wipe all udders. The tanker rejected the bulk milk yesterday for high somatic cell count. The farmer asks whether to treat the cows himself with an intramammary antibiotic he has at home and continue supplying milk to the same tanker.
1. Diagnose the condition and list the immediate actions the farmer should take.
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The hot, swollen quarter, clots, 35% yield drop and high somatic cell count indicate clinical mastitis, most likely bacterial and contagious in this routine. The farmer should separate the milk from both cows immediately and stop adding it to the bulk tank. He should use a strip cup on every quarter, record the California Mastitis Test result, and call a veterinarian. Before antibiotics, an aseptic milk sample should be taken for culture and sensitivity if available. Treatment should be the veterinarian's prescribed intramammary antibiotic, with supportive anti-inflammatory care if advised. The milk must be discarded for the full withdrawal period on the label, and the farmer should not use leftover antibiotic without veterinary direction. Pooling the milk hides the problem and risks residue rejection.
2. Explain how the milking routine spread the infection, and give a corrected routine.
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The single cloth carries bacteria such as Staphylococcus aureus and Streptococcus agalactiae from an infected teat to clean teats, and dipping only after milking does not protect the teat canal before milking. Hand milking can also traumatise teat tissue. The corrected routine is: forestrip each quarter onto a strip cup, wash with clean running water, dry with a single-use towel, pre-dip with an approved teat disinfectant and allow 30 seconds contact, dry, then milk. Milk infected cows last, use post-milking teat dip, clean bedding and keep the lying area dry. Teat cups and hands must be sanitised between cows. Dry-cow therapy and culling of chronically infected cows should be discussed with the veterinarian.
3. The farmer argues that only one can was rejected, so he can still sell the antibiotic milk. Discuss the legal, quality and economic issues.
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Selling milk from antibiotic-treated cows is not permitted. FSSAI rules require that milk be free of antibiotic residues above the maximum residue limit, and residues can cause allergic reactions and contribute to antimicrobial resistance. The tanker rejection for high somatic cell count is already a quality warning; pooling the antibiotic milk would raise the risk of a whole-tanker rejection, penalty or loss of the contract. Economically, discarding a few days' milk from two cows is smaller than losing the daily bulk collection or facing a buyer's penalty. The farmer should record the cow, quarter, drug, dose and withdrawal date, discard the milk as directed, and only return the cow to the bulk tank after the withdrawal period.