Dr. Roger Thomson presented this information for DAIReXNET on April 7th, 2014. You can find the recorded webinar at http://www.extension.org/pages/15830/archived-dairy-cattle-webinars.

1. Milking System Design and Analysis
Dr Roger S. Thomson
MQ-IQ Consulting
Intelligence for a Quality Milk Harvest

2. Milking System Design and Analysis
Goals
Milk clean, dry, stimulated
1. Consistently
2. Quickly
3. Comfortably
4. Completely
Direct cow flow
1. Do not let the parlor run out of cows
2. Do not mix cows
3. Handle cows gently & humanely
4. Max. 3 hours / day for milking

3. Milking System Design and Analysis
Reasons to Change Milking Systems
1. Improve Mastitis Control & Milk Quality
2. Improve Milking Performance (speed and completeness of milk out)
3. Decrease Energy Consumption
4. Decrease Pump Wear w/ Lower Vacuum
5. Decrease Dirt going through Regulator
6. Aesthetic or Cosmetic Reasons

4. Milking System Design and Analysis
System Evaluation Frequency
Annual* - complete system evaluation w/ milking time testing
Biannual* - service and graph pulsators
Monthly* - measure vacuum levels
- perform “Unit Drop Off” test
- measure Effective & Manual reserve
- measure “Vacuum Regulator Efficiency”
- graph pulsators
* - parlors running +18 hrs/day need more frequent evaluation
- parlors running 24 hrs/day = 8760 hrs/year

5. Milking System Design and Analysis
System Evaluation Frequency
Three Key Areas of Concern
1. Regulator / Variable Speed (VS) Drive Function
2. Pulsator Function
3. Liner Function

6. Milking System Design and Analysis
Regular Maintenance
Clean regulators
Monthly
Clean and rebuild pulsators
Direct pulsators = 2500 hours
Indirect pulsators = 4500 hours

7. Milking System Design and Analysis
Regular Maintenance
Tubing and gasket replacements
Milk hoses = 6 months
Twin pulsation tubes = 6 months
Short pulsation tubes = 6 months
Liner Replacement
1200 -10,000 milkings
90 days in small herds

8. Milking System Design and Analysis
Basic Design
Receiver Jar
Sanitary Trap
Milk Line
Pulsator line
Distribution Tank
Air flow
Air flow
Air flow
Vacuum
Vacuum
PumpHP
Must slope to receiver
Vacuum
Regulator

9. Milking System Design and Analysis
Basic Design

10. Milking System Design and Analysis
Basic Design
Sizing a Vacuum Pump to a Parlor
1. Basic milking system needs 35 CFM’s
(a single milking unit uses between 30-40 CFM’s)
(3/4” milk line inlets increases this up to 60 CFM’s)
2. Each milking unit uses approx. 2-3 CFM’s
3. Each horsepower (Hp) should produce 10 CFM’s
(lobe pumps – 85% efficient)

11. Milking System Design and Analysis
Steady Vacuum Level Critical
Requires:
1. Regulator
2. Variable Frequency Drive (VFD)

12. Milking System Design and Analysis
System Evaluations
Cardinal Rule:
Air In
Air Out
Vacuum
Vacuum
Dr Andy Johnson
AABP Milk Quality Pre-conference Short Course

13. Milking System Design and Analysis
Testing System Vacuum Levels
Receiver Jar
Sanitary Trap
Milk Line
Pulsator line
Distribution Tank
Air flow
Air flow
Air flow
Vacuum
Vacuum
PumpHP
Must slope to receiver
Vacuum
Regulator
Vacuum Level (“ Hg)
Air Flow (CFM’s)

14. Milking System Design and Analysis
Milking Unit / Cluster

15. Milking System Design and Analysis
Milking Claws – bottom unload; top unload; various shapes
Inflations – rubber or silicone; round, triangle, square, oval
narrow, medium, large or taper bore
vented or non-vented
Shell- metal; plastic; weighted; non-twist; reusable; throw-away

16. Milking System Design and Analysis
Shut-Off – claw; milk line manual or automatic
flow sensor; meter

17. Milking System Design and Analysis
Pulsators -

18. Milking System Design and Analysis

19. Milking System Design and Analysis

20. Milking System Design and Analysis
Pulsator Graphs

22. Milking System Design and Analysis
Steady Vacuum Level Critical
3 Tests to Evaluate Air Flow Status
1. Unit Drop Off
2. Effective Reserve
3. Manual Reserve