Dairy1- Milking Machines

  1. Contrary to milking a cow by hand, machines remove milk by _________.
    simple vacuum
  2. Milking machines can promote mastitis through: (5)
    changing bacterial numbers on teats (contagious pathogens), altering host resistance (teat damage), provides forces to overcome resistance of teat canal, dispersion of bacteria within the udder (liner slip), udder evacuation (incomplete removal of milk- growth medium for bacteria)
  3. What key machine factors affect mastitis and should be paid special attention by veterinarians? (3)
    stable and appropriate vacuum, adequate pulsation, appropriate removal
  4. What are the components of a cluster? (4)
    teatcup (inflation and shell), claw (short milk tube and short pulsator hose), long milk hose, long pulsator hose
  5. Describe the liner during the rest phase.
    collapsed down on the teat
  6. Describe the liner when vacuum is applied.
    liner open...milk is coming out of teat
  7. Describe the liner when air is admitted.
    liner collapsed due to vacuum inside liner and atmospheric pressure in pulsation chamber
  8. What parts of the milking system are under constant pressure? (3)
    long milk hose, the claw, and the short milk tube
  9. What parts of the milking system alternate between vacuum and atmospheric pressure? (1)
    long pulsator tube
  10. What should the vacuum be in a cluster?
    10.5-12.5 inches of Hg
  11. What is the "trap"?
    separation between the sanitary side (milk side) and the non-sanitary side (pulsation side)- both contain equal vacuum- traps prevents milk from getting into the non-sanitary side
  12. Vacuum stability near the ________ is critical; __(2)__ is required for teat skin health.
    teat end; pulsation of adequate time and force
  13. What is the path of milk flow starting at the cow?
    cow--> cluster--> long milk hose--> milk line--> receiver jar--> plate cooler--> bulk tank
  14. What is the path of vacuum creation starting at the pump?
    pump--> vacuum supply line--> balance (distribution) tank--> sanitary trap--> milk receiver (sanitary)
  15. How are vacuum pumps sized?
    cfm- extraction capacity at a standard operating vacuum
  16. What determined how many cfm a system needs? (2)
    number of units, clean-up of system
  17. What's the conversion of cfm to HP?
    1HP = 10cfm
  18. What are the 2 different types of vacuum pumps?
    standard pump (one constant speed) and variable frequency drive pump (changes speed to correspond to air extraction needs)
  19. Ability of a pump to create/maintain vacuum is expressed as ___________, which is measured as cfm.
    airflow capacity
  20. The main airline extends from the _________ to the ________; its main function is...
    sanitary trap; vacuum pump; keep vacuum from dropping more than .75 inches Hg b/w these 2 points.
  21. What is the function of the vacuum balance tank (distribution tank)?
    provide large mass of vacuum
  22. What are the 1 incoming and 3 outgoing connections from the balance tank?
    • Incoming: pump
    • Outgoing: 1 line leading to sanitary trap, 2 lines leading to looped pulsator line
  23. What is the function of the vacuum regulator?
    admits air to maintain a set vacuum on the non-sanitary side
  24. Where is the vacuum regulator within the system?
    main vacuum line near the trap (as close to the cow as possible, but still on the non-sanitary side)
  25. Why is pulsation necessary?
    to relieve edema and congestion in the teat (this would occur if we applied constant vacuum to the teat)
  26. With pneumatic pulsation, the switching mechanism is driven by _____________; with electric pulsation, switching mechanism is controlled by _____________.
    vacuum; electric
  27. What are the 4 phases of pulsation?
    • A-building vacuum- liner beginning to open
    • B- full vacuum- liner completely open
    • C- losing vacuum- liner beginning to collapse
    • D- no vacuum in chamber- liner collapsed
    • (A+B= full milk cycle; C+D= full rest phase)
  28. What information do we glean from testing pulsators? (3)
    pulsation ratio, pulsation rate, milk:rest ratio
  29. Amount of vacuum/pressure difference required to force liner to collapse during rest phase.
    collapse force/ touch point pressure differential
  30. What parameters are you evaluating when you're evaluating the machine? (2)
    appropriate/stable vacuum, pulsator function
  31. What parameters are you evaluating when you evaluate the milking technique? (8)
    routine, udder prep, stimulation (let down), hygiene, machine removal, residual milk (strip yields), post-milking hygiene, timing
  32. What parameters are you evaluating when you evaluate the cow? (3)
    teat skin health, hygiene, behavior
  33. What is different about the manual reserve test, and when do you perform manual reserve?
    same as effective reserve except regulator is disabled; systems with conventional non-VFD pumps
  34. The amount of air (cfm) admitted to drop the set (system) vacuum 0.6"Hg with the regulator functional.
    effective reserve
  35. What is reserve air capacity an initial measure of?
    potential to maintain stable vacuum [pump capacity, ability to transfer vacuum to the receiver, and the efficiency of the regulator system]
  36. The amount of air that can be admitted to the system and only experience an insignificant drop in vacuum.
    reserve air
  37. What is the goal of measuring vacuum drop at unit fall off?
    mimic a unit fall off to determine how the system responds
  38. What are common problems with pulsators? (3)
    B phase not getting vacuum, various shapes of A and C phases, D phase not getting zero or not going long enough
  39. Difference in ratio b/w sides of a single unit measured when evaluating pulsators.
  40. When measuring pulsators, maximum vacuum should reach __________.
    system vacuum
  41. What is the most important measure in milking machine analysis?
    teat end vacuum
  42. When do you want measurements for teat end vacuum during the milk cycle? (2)
    at peak milk flow and at the end of milking
  43. What are the 2 types of vacuum fluctuations?
    differential fluctuation, cyclic/non-cyclic fluctuation
  44. Differential fluctuation is often due to ___________; other reasons include... (3)
    lifting milk [3" on high line and 1" on low line]; inadequate reserve, plumbing problem, blocked milk vents on the claw
  45. Cyclic fluctuations are associated with __________, but they may indicate ___________.
    milk flow; inability of milk to get away from the teat end
  46. Non-cyclic vacuum fluctuations are usually the result of ___________.
    accidental air admission
  47. What are possible causes of inadequate or unstable teat end vacuum?
    inadequate effective reserve, inadequate vacuum control (vacuum changes too much with system), vacuum unable to get to claw (milk line or claw flooding, other plumbing problems)
  48. What is the DVM goal when evaluating milking systems?
    ID if there is a problem, MAYBE determine a likely remedy...call the dealer
  49. What are key aspects of machine evaluation? (5)
    effective reserve, unit fall off test, teat end or claw vacuum, pulsator curves, milkline vacuum
  50. What is the goal when evaluating milkline vacuum?
    look at vacuum stability over time in line of heaviest milk flow (near receiver)
  51. What places are usually measured when determining plumbing adequacy in a whole system? (4)
    milk receiver, near pump, near vacuum regulator or sensor, on far end of pulsator line [should all be very close to the same]
  52. Vacuum stability near the teat end is evaluated through... (3)
    claw/teat end vacuum, reserve air capacity (effective reserve), vacuum drop on milking unit fall off
  53. What parameters are measured prior to milking? (3)
    reserve air capacity, vacuum drop on milking unit fall off, evaluation of pulsator function (ideally done at milking)
  54. What parameters are measured at milking? (2)
    evaluation of pulsator function (ideally), vacuum stability near the teat end
  55. Describe the important components of the proper milking routine? (7)
    pre-strip, 30 lag time minimum after predip/strip, single service towel, attach unit within 2 min of first contact, adjust unit alignment if necessary, shut of vacuum before removing unit, post-dip
  56. Adding a liner with a vent reduces _____________ during ___________, but ESPECIALLY during _________.
    mouth piece vacuum; peak flow; low flow
  57. What are possible causes of teat base ringing (poor teat ends)? (7)
    high milk vacuum, aged liners, large chamber mouth pice, mismatch of liner and teats, over-milking, teat cup crawling, small lip diameter on mouth piece
Card Set
Dairy1- Milking Machines
vetmed dairy1