Development, validation, and demonstration of the rotary parlor model

Area of Science:

• Agricultural Engineering
• Dairy Science
• Farm Management Systems

Background:

• Rotary milking systems aim to decrease labor in dairy farming.
• Identifying optimal strategies for efficient milking is crucial for dairy operations.

Purpose of the Study:

• To develop and validate a mechanistic model (Rotary Parlor Model - RPM) for simulating rotary parlor milking efficiency.
• To analyze the impact of parlor size, rotation time, and automatic cluster remover (ACR) thresholds on milking efficiency.

Main Methods:

• Developed a process-oriented model (RPM) using data from commercial and research dairy farms.
• Validated the RPM against empirical data for milking process time, cows/hour, and liters/hour.
• Simulated various parlor sizes and rotation times, and conducted sensitivity analysis on ACR thresholds.

Main Results:

• The RPM demonstrated high accuracy with low mean absolute percentage errors (≤3.5%) for key efficiency metrics.
• Decreasing rotation time significantly improved efficiency, especially in larger parlors (e.g., 26% increase for 60-cluster vs. 3% for 40-cluster).
• Increasing ACR thresholds reduced individual cow milking duration, decreasing go-around cows and enhancing overall efficiency, with greater impact in smaller parlors.

Conclusions:

• The RPM provides valuable insights into factors affecting rotary milking efficiency.
• Optimizing rotation time and ACR settings are key strategies for improving labor efficiency in rotary milking parlors.
• The study quantifies the complex interactions between parlor design, operational parameters, and herd characteristics on milking performance.