EFFECT OF THE DURATION OF THE C PHASE OF PULSATION ON MILKING PERFORMANCE
Aaron K. Kochman1, Chuck Laney1, Stephen B. Spencer2
1Lauren AgriSystems, Ltd., New Philadelphia, OH, USA
2Spencer Consulting, State College, PA, USA
Pulsation is defined as the cyclic opening and closing of a liner by ISO 3918-2007. Pulsator rate and ratio are typically the main focus when it comes to characterizing the pulsation system. The pulsation cycle is divided into four phases as: The a phase or liner opening, the b phase or the liner open or milking phase, the c phase or liner closing, and d phase or liner closed. The objective of this study was to isolate the affects the duration of the c phase has on milking performance. The c phase is defined as the period when the vacuum in the pulsation chamber decreases from the maximum pulsation chamber vacuum minus 4 kPa to 4 kPa in ISO 3918-2007. Studies by Billion et al. (2001) and field observations have shown notable variations in milking performance with differences in the chamber vacuum c phase.
Materials and Methods
A trial using 300 Holsteins milked 3 times daily was carried out at Lauren Dairy, Millersburg, OH. The experiment used a silicone liner with a circular barrel in the open phase and triangular barrel in the closed phase (Lauren Tri-Circle