A push bar serves to nudge or urge cows to leave a milking parlor and move to an exit alley. The push bar is mounted on extendible support members, which may have an inner tube and an outer tube, and which is mounted by a journal onto an overhead pivot. There is one air cylinder to rotate the assembly, and additional air cylinders to extend and retract the support members. A programmed controller ensures that the push tube travels in a generally straight, horizontal path to push the cows out, and then lifts the push tube so it is over the cows' heads on the return.