An automated in-line clinical mastitis detection system using measurement of conductivity from foremilk or individual udder quarters

Authors: Mein GA, Johnstone PT, Sherlock RA, Claycomb RW
Publication: New Zealand Veterinary Journal, Volume 57, Issue 4, pp 208-214, Aug 2009
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant
Subject Terms: Milk, Harvesting/processing, Bacterial, Biosecurity, Diagnostic procedures, Disease control/eradication, Epidemiology, Mammary gland/udder, Mastitis, Infectious disease
Article class: Scientific Article

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Abstract: AIM: To assess a novel method for automatic in-line detection of clinical mastitis.
METHODS: For a brief period at the start of milking for each cow, electrical conductivity of foremilk was measured for each quarter in turn, using a single sensor installed in the long milk tube (LMT) about 1.5 m downstream from the milking-machine claw. Sequential separation of flow between udder quarters was achieved by control of pulsation to individual teat cups within a conventional cluster. The ratio of conductivity values between quarters was used as an indicator of mastitis status. The concept was evaluated initially in a pilot trial in a 200-cow herd milked in a 23-stall swing-over herringbone milking parlour. It was then tested rigorously in a field trial in a 640-cow herd milked in a 50-stall rotary milking parlour. Both trials were conducted in the Waikato region of New Zealand. In the latter trial, sensor results were compared with visual inspection of a commercial in-line mastitis filter fitted to each milking unit. These filters were inspected for clots immediately after every cow’s milking, for 3 weeks. The dataset of approximately 27,000 individual milkings was tested against several published or potential alternative ‘gold standards’ for diagnosing clinical mastitis.
RESULTS: In the pilot trial, 12–14 clinical events were detected out of 19 true clinical quarters, with a false-alert rate of between three and five false electrical-conductivity alerts per 1,000 individual milkings. In the more rigorous field trial, sensitivity ranged from 68 to 88%, and the false-alert rate (false-alert episodes per 1,000 individual milkings) ranged from 2.3 to 7.0.
CONCLUSION: The novel clinical mastitis detection system, based on separation of the flow and measurement of electrical conductivity from foremilk of individual udder quarters, has the potential to provide a new tool for helping farmers to monitor clinical mastitis in herds milked with conventional clusters.
KEY WORDS: Mastitis, conductivity, clinical, detection, quarter

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