Yeti's procedural feathers provide an easy way of texturing with Chaos' VRay rendering engine. 

When a feather object is generated an additional feather_uvw varying vector attribute is exported either as Projected (Default) or Parametric UV coordinates which can be selected on the feather object itself. 

A VRayUserColor node may be used in your shading graph to access this custom attribute to be used downstream where the output R and G values with be the computed U and V coordinates of the feather. 

With this new node created feather_uvw needs to be entered into the User attribute name parameter of the node. 

The R and G values may now be used as input texture coordinates for texture nodes, here used to control a checkered texture.

When rendered the feathers should be texture accordingly.