Rav Huna quoted Rav (023) as saying: “An egg is finished when it comes out.”
Another Explanation: When the majority of the egg comes out, it is considered to have been laid - like Rabbi Yochanan said.
Rabbi Yochanan: If the majority of an egg came out before Yom Tov, but then it went back inside and only came out on Yom Tov, it is permitted.
Some Say: An egg is only finished when it comes out in its entirety, Rav is arguing on Rabbi Yochanan.
We learned above (023): One who discovers finished eggs inside a chicken that he slaughtered, may eat them with milk. Rabbi Yaakov: If they were still connected to the ovary with tendons, it’s forbidden.
Question: Whose opinion does this Beraisa follow?
One who eats of the neveilah of a kosher bird [he becomes tamei and his clothing become tamei as well]; from the egg cluster (attached to the ovary), from the bones, from the ligaments, or from the meat of the bird while it was still alive: he’s tahor. If, however, he ate from the ovary itself, from the gizzard, the intestines, or from liquefied fat: he’s tamei [although these are unusual forms of eating, it’s still considered eating].
So who is of the opinion that eating of the egg cluster is tahor?
Rav Yosef: This is against the opinion of Rabbi Yaakov who holds that as long as the eggs are attached with tendons, they’re considered meat.
Abayye to Rav Yosef: Perhaps a distinction must be made between Issur and Tumah. Rabbi Yaakov is stating that there’s a chumrah d’Rabbonon on eating such eggs with milk, but they’re not actually considered meat. He wouldn’t make such a gezeirah regarding tumah, because we do not increase tumah.

