Assuming you are talking about porting a presentation prepared in Keynote '09 on OSX to be used on an iOS Device such as iPad, you should know that most but not all of the animations will be preserved. Those that can't be replicated in iOS are replaced by Keynote.
Here are two good references for having the least problems between the two platforms that might help:
Keynote for Mac: Best practices for creating a Keynote presentation for animated playback on iWork.com
Keynote for iPad: Best practices for creating a presentation on a Mac for use on an iPad
PS: If you scroll through the builds and animation options on the two platforms you will get the best idea of what is and is not available on each.
Message was edited by: bwfromspring hill