Type of teat cup liner and cluster ventilation affect vacuum conditions in the liner and milking performance in dairy cows
| Autor: | Christina Umstätter, Gro E. Holst, Felix Adrion, Rupert M. Bruckmaier |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
musculoskeletal diseases
Materials science Vacuum Milking law.invention 03 medical and health sciences fluids and secretions Animal science Mammary Glands Animal immune system diseases law Genetics Animals Lactation Milk flow Tube (container) 030304 developmental biology 0303 health sciences technology industry and agriculture 0402 animal and dairy science food and beverages 04 agricultural and veterinary sciences 040201 dairy & animal science Dairying Milk Ventilation (architecture) Animal Science and Zoology Cattle Female Food Science |
| Zdroj: | Journal of dairy science. 104(4) |
| ISSN: | 1525-3198 |
| Popis: | The optimal milking cluster should milk as gently as possible to minimize the mechanical effect on the teat tissue at an optimal milking performance and milk quality. The objective of this study was to investigate the influence of liner shape (round vs. triangular) and type of cluster ventilation (claw vs. mouthpiece chamber; MPC) on milking performance and vacuum at the teat end and in the MPC. Our hypothesis was that liner shape and cluster ventilation affect milking performance and MPC vacuum. Six Holstein Friesian cows were milked twice daily over 12 d with a bucket milker, using 4 different cluster types that combined liner shape and type of cluster ventilation at 3 different system vacuum settings (35, 42, and 50 kPa) in an incomplete randomized block design. Milk flow and vacuum in the MPC, at the teat end (measured in the short milk tube), and in the short pulse tube were continuously recorded during milking. Milk flow was higher, and hence main milking time was shorter, with the round than with the triangular liners. The MPC vacuum was lower in round than triangular liners, which was caused by higher air leakage between teat and liner barrel in the triangular liners. The MPC vacuum, as well as its cyclic fluctuations, increased at the end of milking (immediately before cluster detachment) in all cluster types, with the highest amplitude of fluctuation in the triangular liners with MPC ventilation. The MPC ventilation reduced the MPC vacuum in both liner types at the end of milking, and also in triangular liners during peak milk flow. Despite the observed differences of MPC vacuum, the ventilation type did not affect milking performance. However, milking with triangular MPC-ventilated liners caused an increased proportion of foamed milk, which could potentially have a negative effect on milk quality. |
| Databáze: | OpenAIRE |
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