I've taken DNA samples before to get a bull registered so you can register his offspring. The AHA is doing an excellent job of cleaning up pedigrees and keeping them clean by requiring DNA samples, imho.

A DNA sample for registration just requires a hair sample out of the tail be sent to the AHA. Not an expensive thing at all as I recall.

The rest idea is interesting but the logistics of exchanging bulls every 7 days seems like it might be more difficult in July/August than it seems here in March...