Why change at 2500 milkings

If it was simple then the signal to change liners at 2500 milkings would be obvious. However, liners will still keep working past 2500 milkings if you let them. So why change?


The properties of any liner will deteriorate when used - and the performance of the liner is a major factor in determining the health and condition of the cow's teat. These are gradual processes. By the time you see your somatic cell count go up and your cases of mastitis increasing, it's too late - you have now got a problem which will take a long time and a high cost to fix.


A liner will wear out due to the dynamic nature of the way it is used - it will open and close over 2.5 million times during its use. You will see the liner becoming slack in the barrel and possibly at the mouthpiece. This will increase the forces on the cow's teat. and will increase the chances of liner slip.


The liner is also exposed to some aggressive cleaning chemicals at high temperatures, these can break down the rubber. Even the milk itself affects the liner - butterfats are absorbed, and deposits can be left on the surface.


To the naked eye, a liner at 3000 milkings may look clean, but a microscopic examination gives a different picture. The photograph below (Picture 2) shows the surface magnified 200 times - these are sites for bacteria growth, and the also harden the liner surgace making it abrasive, which can the damage the teat.


Between 2000-3000 milkings we can see the levels of reddening and damage to the teat increasing. The teat then loses its natural resistance to bacteria and pathogens, leading to higher somatic cell count and incidents of mastitis.


So, a disciplined approach to changing liners at 2500 milkings will improve the health of your herd and the quality of your milk.

days based on 2500 cows, milkingtwise per day
milking cowas in herd 400 12 14 18 24 30 36 44 48 60 72 90
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milking units