Just got off the phone with John from Mini Tube. They have a new extender (10 day) that does not require egg yoke to be added. It's called AndroPRO ChillGuard LT. I can't tell you how many eggs I've ruined trying to get just the yoke!! ;-)
Here's the link to it:
http://www.minitube.com/Protocols/canine/AndroPRO_LT_Protocol.pdf
LOL yeah, I need chickens all right. Something else to feed and pick up poop after!!! ;-) You workin' on that Shrimp and Grits luncheon for the Specialty?? YUM