I understand that there’s a yeshivish tradition of referring to Masekhes Beitza as “Bei’a”, by way of using the Aramaic word for ‘egg’ in place of the Hebrew. In two separate online shiurim that I have listened to (dafyomi.org and realcleardaf.com) the maggid shiur not only does this, but continues replacing every instance of “beitza” with “bei’a” in the gemara as well.
And yet, wherever the word beitza appears in other masekhtas (eg: at the bottom of Shabbes 19b), the maggid shiur in question keeps it as “beitza”.
Where does the tradition of replacing the Hebrew with the Aramaic come from, and why is it done only in this one masekhta? It is obviously not an issue with the word itself, but an issue with its appearance in this particular tractate. What is the reason for that, and when did this tradition develop?