The Last Can at the Village Collection Centre
At a village dairy collection centre in Kolhapur, 1,150 L of morning milk is received from nine pourers. The centre's written acceptance limit is acidity not more than 0.15% lactic acid and MBRT at least 3 hours. The last can, 60 L from a farmer, arrives at 9:40 a.m. with milk temperature 34 °C. Its titratable acidity is 0.19% lactic acid and MBRT is 1.5 hours; the milk smells slightly sour. The bulk tank sample taken just before this can was added shows 0.14% acidity and MBRT over 5 hours. The farmer says the can was washed with the same cloth used for the cattle shed and that the milk was held since 6 a.m. because of a power cut. The centre has one 1,000 L bulk cooler, a lactometer, a butyrometer and a chlorine test kit, but no laboratory incubator beyond a small water bath.
1. Decide whether the 60 L can should be accepted, rejected or handled separately. Justify the decision using the test results and state the payment decision.
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Decision: reject the 60 L can and do not add it to the bulk tank. The centre's standard is acidity not more than 0.15% lactic acid and MBRT at least 3 h. This can is 0.19% and 1.5 h, and it is already slightly sour. MBRT is a bacterial-load test; 1.5 h indicates heavy contamination, not a minor handling fault. Adding 60 L to 1,090 L would not make it safe by dilution: it would introduce spoilage organisms and enzymes that reduce the keeping quality of the whole tank. Pay only for the accepted 1,090 L. Return the rejected can or, if the farmer disputes the result, seal a sample and send it to the district laboratory, recording the result. The bulk sample at 0.14% and more than 5 h may be accepted, but it should be cooled and dispatched promptly. The rejected milk must not enter the market-milk chain.
2. Identify the most probable causes of the failure and give practical advice to the farmer.
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The probable causes are: (i) holding the milk for about 3 h 40 min at 34 °C, which allows rapid bacterial growth; (ii) washing the can with a cloth used in the cattle shed, which adds manure and fodder bacteria; and (iii) no cooling during the power cut. The cow is not the main issue; handling is. Advice: rinse the can with clean water, scrub with a dairy detergent, sanitise with chlorine solution (about 100–200 ppm available chlorine), and drain upside down. Use a clean cloth only for milk utensils; never use a shed cloth. Deliver within 2 h of milking. If power fails, keep the can in the coolest place and use ice if available. Do not mix evening and morning milk without cooling. Give the farmer a written slip showing the test result so the correction is specific.
3. Propose a monitoring plan for the collection centre for the next month.
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A workable plan is: (1) record the temperature of every can at receipt and flag cans above 10 °C for priority testing; (2) test acidity on every can and MBRT or resazurin on a rotating basis, keeping results by pourer; (3) test one composite sample weekly for starch, detergent and urea, and check the water supply chlorine level; (4) calibrate the lactometer and butyrometer and check sanitizer strength daily; (5) hold a monthly farmer meeting and use a penalty/incentive system based on recorded results; (6) review rejection data weekly and target the three worst pourers first. This is a control plan, not a one-time test; the records should show whether the rejection rate falls.