Dr. Rupert Bruckmaier delivers 2024 Tucker Lecture
Annual lecture continues with new perspectives on dairy physiology.
In September, the Animal Science Department had the privilege of hosting Dr. Rupert Bruckmaier as the 2024 Dr. H. Allen and Ann Tucker Lecturer. Dr Bruckmaier recently retired from the University of Bern in Switzerland after a productive career as a veterinary physiologist. Dr Bruckmaier’s research focused on milking physiology. His talk was called “Advancing dairy production: Should we select cows that fit our technology or develop milking technologies that alight with lactation physiology?” Below are some highlights of his lecture.
Mammary physiology
The physiology of the cow’s mammary gland is why farms must plan the milking routine to achieve a good milk let-down response and match this response timing with unit attachment. To milk the cows gently and efficiently, farms must provide proper stimulation during milking with the help of liners and pulsations. Dr. Bruckmeier shared some examples of using parlor technology to improve the alignment with lactation physiology.
Changes of vacuum at the teat end during milking
Teat end vacuums in low lines systems have small drops during and at the end of milking. New technology allows the measurement of the mouthpiece chamber (MPC) vacuum. The group measured the MPC vacuum and saw that it remained low while there was high pressure inside the teat. This is because there was a good seal between the liner and the teat, and because the liner lip allowed some degree of air entrance. When a quarter is done milking, the internal pressure of the teat decreases, the seal between the liner and the teat is lost, leading to an MPC vacuum increase. Therefore, MPC vacuum pressure is a marker for the cessation of milk flow by quarter.
Milking with increased pulsation ratio in rear quarters
The group milked the rear quarters faster by increasing the pulsation ratio to 80:20. The front quarters were milked normally with a pulsation ratio of 65:35. They did not observe any negative effects on the teats. There was no over milking overall, they saw shorter machine-on times and reduced time of milking while the front teats were empty.
The goal is to find the optimal interplay between the cow’s milk ejection – the squeeze - and the milking machine – the suck. To improve the squeeze, the only option is optimizing the udder preparation. But we can adjust the suction side with modern technology to ensure optimal milking. It is the task of physiologists and researchers to work with the dairy technology groups in finding opportunities for improvement.
To learn more about Dr. Tucker or view the recorded lecture, go here.