The SlideAndZoom animation which is played when changing the ViewDeifintions, comes from a TransitionControl placed in the RadScheduleView ControlTemplate. So you should modify the template in order to remove the animation.
I would suggest to use Implicit Styles to style RadControls as explained in the following article:
You should go to Telerik.Windows.Controls.ScheduleView,xaml and search for "PART_TranstionControl" - the Name of the used RadTransitionControl. Then just set the Duration of the animation to "0":
Hope this helps.
the Telerik team