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Pressure distribution at the teat-liner and teat-calf interfaces
P P J van der Tol1, W Schrader, B Aernouts
1Lely Industries NV, Weverskade 110, NL-3147 PA Maassluis, the Netherlands. rvandertol@lely.com
Journal of Dairy Science
|January 12, 2010
Summary
Milking machine liners can cause teat-end injuries due to uneven pressure. Some liner designs distribute pressure more evenly, reducing injury risk and potentially leading to more natural milking techniques.
Area of Science:
- Veterinary Medicine
- Animal Husbandry
- Biomechanical Engineering
Background:
- Milking machines apply vacuum and pressure, potentially causing teat-end injuries and hyperkeratosis.
- Understanding pressure distribution is crucial for preventing bovine teat damage.
Purpose of the Study:
- To test the hypothesis that collapsed milking liners create uneven pressure distribution on bovine teats.
- To compare pressure distribution patterns of different liner designs and a suckling calf.
Main Methods:
- Utilized pressure-sensitive sensors (approx. 2 gauge points/cm²) to measure pressure at the teat-liner and teat-calf interfaces at 100 Hz.
- Tested 7 different artificial teat liners, one liner at 3 vacuum levels, and a suckling calf.
- Included in-vivo measurements on one cow during machine milking.
Main Results:
- Conventional round liners concentrated pressure on two sites at the teat end.
- Softer liners with reduced tension, smaller barrels, and shallower mouthpieces distributed load over a larger area.
- While all liners applied highest pressure at the teat end, some designs reduced this pressure by 25% at 44 kPa vacuum.
- A suckling calf utilized suction and overpressure, reducing vacuum during swallowing and avoiding direct teat-end loading.
Conclusions:
- Pressure distribution varies significantly among different milking liner designs.
- Certain liner modifications can reduce peak pressures at the teat end, mitigating injury risk.
- Calf suckling presents a different, potentially less injurious, pressure profile compared to machine milking.
- Pressure sensor technology offers a viable method for analyzing teat loading and developing improved milking systems.
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