What are the primary categories of treifot? Ulla states that eight categories that were transmitted as halakha to Moshe from Sinai: perforated (nekuva), severed (pesuka), removed (netula), deficient (chasura), torn (kru'a), clawed (drusa), fallen (nefula), and broken (shevura). Chiya bar Rav said there are eight cases in the category of perforated, and this excludes the gall bladder, which is considered a treifa only by Rabbi Yosi b'Rabbi Yehuda. However, Rabbi Yitzchak bar Yosef said in the name of Rabbi Yochanan that the ruling is like Rabbi Yosi b'Rabbi Yehuda. He brings a proof for Rabbi Yosi's position from a verse in Iyov 16:13, in which Iyov explains that his gall bladder was poured on the ground, and yet, he still lived. The rabbis' retort to that is that Iyov's situation was miraculous and we cannot derive halakha from a miracle. Another ruling of Rabbi Yochanan was brought by Rabbi Yitzchak bar Yosef regarding the liver – if the liver is reduced to less than an olive bulk, the animal is a treifa. If, according to Rabba bar bar Hanna, Rabbi Yochanan holds like an unattributed Mishna, there is a contradiction as our Mishna rules it is a treifa only if the liver is completely removed. This is resolved by explaining there is a debate between the two amoraim what Rabbi Yochanan held. Two other rulings are brought by Rabbi Yitzchak bar Yosef in the name of Rabbi Yochanan regarding treifot. A gall bladder that was perforated but the liver covered up the hole, or a bird's gizzard that was perforated, but the inner lining was not, both are kosher. Raba notes that the gullet consists of two distinct linings - an outer red membrane and an inner white membrane. If only one layer is punctured while the other remains intact, the animal remains kosher. What happens if both layers of an organ are punctured, but the holes do not align? Rav Ashi rules that in a stationary organ like the gizzard, non-aligned punctures are kosher because the layers do not shift. However, in a dynamic organ like the gullet, which constantly expands, contracts, and moves during feeding, the holes are liable to realign; therefore, non-aligned punctures render the animal a treifa. In one version, Mar Zutra quotes Rav Papa saying the opposite; in another, he agrees. Raba notes that the gullet cannot be evaluated for predatory clawing (safek drusa) from the outside, as the outside is red and blood would not be noticeable. It must be inverted and inspected from the inside. If a thorn is found lodged inside the gullet with a perforation on the inside, but no noticeable perforation on the outside, Ulla rules that we do not fear it caused a perforation which healed, as free-roaming livestock regularly consume thorny vegetation without injury. Is the turbatz haveshet, the uppermost part of the gullet, legally treated as part of the gullet? Rav and Shmuel disagree on its status. Rav maintains it is a valid location for slaughter; thus, any extraneous puncture of even a minimal size renders it a treifa. Shmuel argues it is not a valid location for slaughter, meaning it is only rendered a treifa if the majority of it is severed. This dispute culminated in a practical case involving an ox belonging to the sons of Rav Ukva, where the slaughter began in the turbatz haveshet and finished in the gullet. Rava applied the stringencies of both Rav and Shmuel, declaring the animal a treifa. Rabbi Abba reversed Rava's decision, demonstrating that the ox was completely kosher under either authority individually. If one followed Rav, the slaughter location was valid; if one followed Shmuel, the minor cut in the turbatz haveshet did not render it a treifa before the slaughter was completed. Because Rava's logically contradictory ruling caused an impermissible destruction of kosher property, Rabbi Abba ordered Rava to financially compensate the owner of the ox.
