Three others who also got trapped in the mishap, were rescued late last night and shifted to hospital, where their condition is stated to be serious, Kanpur SSP Shalabh Mathur said.
The incident occurred yesterday night after the bovine fell into the borewell in a farm belonging to one Avdhesh Yadav (28) at Chandanpur village in Maharajpur area here.
Yadav along with a friend Putan (23) entered the ditch and tied a rope around the animal, while three others-- Pratap (30), Abhimanyu (20) and Suraj -- tugged at it from above.
Police along with an NDRF team carried out rescue operations through the night and also pressed an excavator into service.
While Pratap, Abhimanyu and Suraj were rescued alive, the other two were found dead this morning.
Police have sent the bodies for post-mortem.