100 jobs are to go in Sligo.
Elanco Animal Health, a subsidiary of Eli Lilly and Co., has announced the closure of its manufacturing facility.
The company provides animal health products in more than 70 countries and employs 6,500 people.
The closure comes despite restructuring last year.
The company has said a small number of staff will support product transfer and decommissioning activities throughout 2016 and into next year.