My object isn't fully Rendered, but in viewport is alright I come to you today with this issue.
I've just start blender course @blenderguru (I really enjoy it;)).
As you can see (in render) my icing is gone... but sprinkles are there. And when I check it in blender viewport everything is alright. I am just starting learning, so please be nice :)

Rendered image (icing doesn't show up)  



Here's how it looks like in Rendered Preview  



And here's an image of my particles settings  



P.S.: If it can help here's the blender file
You have to enable Show Emitter option, in Particles Settings.

It's often useful to have the emitter hidden, but in this case it is also an important part of your object.  

Enable it here:
Properties Panel > Particle Settings > Render