1. MILKING SYSTEM AVS 172 AMIN AHMAZADEH Ph.D.
References Dr. H.D. Tyler, Iowa State University and Dr. M. A. Barnes, Virginia Tech

3. Air intake line
exhaust
Vacuum pump
condenser

4. 4. Balance Tank
5. Regulator

5. 4._________________

6. Pulsator
Pulsation line
Pulsation Hose
Carries vacuum to milking unit (fed by reserve tank)

7. 7.Pulsator
Pulsation Hose
6. Pulsator Vacuum line

9. 7.Pulsator
Milk Hose
Milk hose: delivering milk from the udder to milk line
10. Milk Line

11. 10. Milk Line

12. ---------------------------

13. 11. Receiving Jar

14. 12. Milk Pump
Pumping milk from receiving jar to the milk tank

15. 14.Sanitary Trap

16. Cooling Plates
Decreasing milk temperature before is stored in the milk tank

17. Cooling system Control
13. Milk Tank
Cooling system Control

19. Milking Equipment Milking unit
Each has four individual teat cups attached by hoses to a unit pulsator
Each teat cup has a teat-cup liner

20. Fig The milking claw is designed to harvest milk with the least amount of damage to teat end tissues (Courtesy of Westfalia)

21. Fig Teat cup liners must be replaced at regular intervals to maintain optimal function of the milking system (Courtesy of Westfalia)

22. Milking Systems; pulsators
allow alternating vacuum/atmospheric pressure into teat cup chamber
attached to pulsator vacuum line
1 pulsator/milking unit

23. Pulsation: Milking Phase Resting Phase
Milking Phase is the expansion phase
Massage phase
Initiated when air is pumped into the space between the liner and outer shell

24. Fig Vacuum diagrams visually display the inner workings of the teat cup liner, allowing otherwise invisible problems to be detected (Courtesy of Westfalia)

25. Fig Proper milk let-down procedures stimulate dilation of the teat sphincter, permitting faster flow of milk from the teat end and more rapid milking times (Courtesy of Westfalia)

26. Milking Systems; pulsators
Pulsation rate:
vac/atm = milk/massage
Pulsation ratio:
wider = faster milk out
too wide increases congestion

27. Fig 32-9. The mechanics of machine milking (Courtesy of Iowa State University)

28. Back Flush

29. Milk Flow Rate
Controlled by pressure differential around the streak canal
Determined by pressure exerted by the milk in the udder and pressure exerted by vacuum pump and pulsator
Controlled by size and tautness of streak canal
Can be affected by intensity of stimulation, age of cow, effects of teat injury

30. Fig 32-13. Changes in milk flow rate during the milking cycle (Courtesy of Westfalia)

31. Milking Procedures Prepare equipment Preparing the cow
Assemble and sanitize
Preparing the cow
1) Clean cows teat and pre-dip 2)
3) Strip 2-3 streams of milk from each teat
Examine for evidence of mastitis
4) Make sure you have a full ten seconds of teat end stimulation

32. Fig Whether using paper or cloth towels, it is important to thoroughly dry teats, especially teat ends, prior to applying the milking machine (Courtesy of Howard Tyler)

33. Fig Strip cups can be used to check for the presence of clots in milk strippings (Courtesy of Iowa State University)

34. Milking Procedures 5) Attach teat cup and begin
Approximately 45 seconds after stimulation, attach teat cup
Most cows will milk out within 3-6 minutes
6) Removing the teat cup
Remove when flow rate is less than two pounds per minute
Automatic take-offs
Following milking dip teats with disinfectant solution 7)

35. Fig Kinking inflations prior to attaching milking units minimizes air leaks and vacuum fluctuations at the teat end (Courtesy of Howard Tyler)

36. Fig Post-milking teat dipping is important to protect the mammary glad from pathogen entry until the teat sphincter closes (Courtesy of Westfalia)

37. Fig Clean-in-place systems allow milking units to be cleaned and sanitized in the parlor between milkings (Courtesy of Westfalia)