Dairy Crest Crudgington Creamery closure starts
Workers will leave Dairy Crest's Crudgington Creamery in Shropshire will go next month, the firm has told the USDAW union.
Plans to close the site, risking its 161 jobs, were revealed two years ago.
Dairy Crest said the departure of "a proportion" of staff marks the start of the plant's closure, although it is has not said when it will completely shut.
The move is part of a "drive to improve efficiency" and could see about 50 jobs transferring to Kirkby, in Liverpool.
Dairy Crest transferred production of Clover butter from Crudgington to Kirkby in 2012, with the loss of about 90 jobs.
In January it closed its Whitland dairy, in Carmarthenshire, blaming falling sales and rising costs.
Thirty-one jobs were lost and milk production transferred to Stonehouse, near Stroud in Gloucestershire.