It's after hundreds of new cases of Covid-19 at the facilities has led to a localised lockdown in Kildare, Laois and Offaly.
150 workers tested positive for the virus at Kildare Chilling, 86 at O'Brien Fine Foods in Timahoe and nine at the Irish Dog Food Factory in Naas.
Carroll Cuisine in Tullamore, which has reported nine cases, will re-open but is undergoing a deep-clean.
SIPTU will meet with the Meat Industry later to discuss the outbreak among workers.
Agriculture Minister Dara Calleary says his department are working on revising health protocols for meat processing plants:
