May is fast turning into June and for dairy farmers, it may be time to start looking at changing the liners in their milking parlours.

The liner is the only part of the milking machine that comes into contact with a cow and they are expected to last for 2,000 milkings or six months, depending on which comes around first.

However, if a herd has increased in size, they need to be changed more often than this.

Changing liners

The major factor that determines when liners need to be changed is the number of cows going through the parlour.

A farmer milking nine rows of cows means their liners are completing 18 milkings/day, so they need to be changed every 111 days (2,000/18 = 111 days).

This means that the liners in this parlour need to be changed at least twice a year in a spring-calving herd with a two-month dry period.

If calving began in early February on this farm, they would need to be changed in the coming few weeks.

When changing liners it is important that the new ones are installed correctly, as failure to do so will result in cows not being milked properly.

When the liners are being changed is also a good time to fix any other issues you have seen in the parlour.

There are a lot of parts of the milking machine that can become worn, for example the milk line or pulsation tubes should be checked to ensure they are not frayed or damaged.

You should also check the bowl/cawl for any damage or that the air hole is not blocked.