GMB pushed for the extra days after discovering that the affected members – who work in night hygiene - were not receiving sufficient time off for their shift patterns.
The additional time off will greatly improve their work-life balance and overall staff morale.
Steve Garelick, GMB Regional Organiser, said:
"This is a fantastic outcome for our members at Pilgrim’s.
“It shows what can be achieved when unions and management engage in meaningful dialogue.
“Six extra days of holiday will make a real difference to these workers and their families.”
Rupinder Sandhu, GMB representative and Pilgrim’s employee, added:
"We are so grateful for GMB's hard work and dedication.
“Getting these extra holiday days is a huge boost for us.
“It means more time with loved ones, more time to recharge, and it truly makes us feel valued by both GMB and Pilgrim’s Food Masters."