What is the purpose of a record in "Breeding Records"? Doesn't it document a breeding event by recording the ID's of one male, one female and the date?
The Genotype, DOB fields should not be in this table at all. A relationship by Animal ID to Mouse Records can make that data accessible without needing to copy it. Status might or might not also be omitted depending on whether you want to always see the animal's current status or capture the animal's status at the point in time when this breeding event was documented. You can set up an auto-enter field option to copy over the value of status if you want this latter option.
Your relationships would seem (to me) to be:
MouseRecords|Male::AnimalID = BreedingRecords::AnimalID_Male
MouseRecords|Female::AnimalID = BreedingRecords::AnimalID_Female
MouseRecords|Male, and MouseRecords|Female would be two different table occurrences of MouseRecords. BreedingRecords::AnimalID_Male, and BreedingRecords::AnimalID_Female can be formatted with value lists for selecting the correct records for this breeding pair.
Once you have selected the Mail and Female parent, you can place fields from MouseRecords|Male, and MouseRecords|Female on a BreedingRecords layout to show data from the selected MouseRecords for these two mice. You can also put a portal to BreedingRecords on a MouseRecords|Male layout and include fields from MouseRecords|Female in the individual portal rows to show information about each breeding event. And you can do the opposite of this on a layout based on MouseRecords|Female.