About 950 union members rejected a tentative agreement with Cargill and shut down the biggest beef-packing plant east of Alberta.
The plant on Dawson Road, Guelph, can slaughter 1,500 cattle a day.
Eight-two per cent of those who voted turned down the deal their union leaders had negotiated.
Union leaders said they will press for a better deal than the four-year one they had signed that included raises every year.
