Larry Wolfe of Teamsters Local 453 in Cumberland said Friday the 55 workers walked out Wednesday night. He says most of the striking employees work at a Cumberland processing plant. The others drive trucks based in Oakland; Moorefield, W.Va.; and Culpeper and Broadway, Va.
Potomac Farms is owned by Galliker Dairy Co. of Johnstown, Pa. The company didn't immediately return a call Friday from The Associated Press.
Wolfe says the strike follows workers' rejection of a contract offer that would end company contributions to a pension plan.
He says the previous contract expired in February 2011.