You will not be able to get around this without extra plugins.
Have a look at Solid Spline or Storm Tracer if you want to make spline visible in a rendering without having to work with a Sweep NURBS object.
This will not ease the process of the splie creation, though.
A total different thing might be interesting if you have to do such animations more often. Have a look at XFrog (
http://www.xfrogdownloads.com/greenwebNew/news/newStart.htm). It offers organic modelling and animatin of plants within C4D.
Kind regards,
Arndt von Koenigsmarck
http://www.vreel-3d.de
http://www.vonkoenigsmarck.de