Strike action will take place from April 1-7. Work to rule will be in affect from April 8-14, before all out indefinite strike action begins on April 15, said Unite.
The workers, based at mills in Suffolk, Norfork, Oxfordshire, Fife, Devon, Lincolnshire and East and North Yorkshire, rejected an imposed pay offer of 4.5%.
The dispute is also over AB Agri’s failure to recognise the mill workers as a national bargaining unit represented by Unite.
According to Unite, the company’s efforts to undermine collective bargaining and its refusal to allow staff, mainly at its Flixborough site in Lincolnshire, to pursue voluntary redundancy are at odds with its membership of the Ethical Trading Initiative.
Unite regional officer Mark Jaina said: “AB Agri’s attempts to union bust won’t work and contravene its membership of the Ethical Trading Initiative. The only way the company can end this dispute is to stop its attacks on the Flixborough workforce, recognise the union and put forward an offer our members can accept.”
The union said the strike action will cause significant disruption to the operations of AB Agri mills, which produce a huge proportion of the UK’s pig and poultry feed.
AB Agri has not yet returned our request for comment.