Since we are allowed to prepare food on Yom Tov, in the event that fresh meat is needed, slaughtering an animal would be permitted. (It is worthwhile to note that the only way meat could be kept fresh during Talmudic times – prior to the invention of refrigeration – was by keeping the animal alive until it was to be cooked.) Sheḥiṭa must be done with a specially prepared knife that is perfectly smooth with no chinks or nicks. The Mishna on our daf forbids sharpening a knife on Yom Tov, but the Gemara permits it under certain circumstances.
Rav Yosef rules that a knife which became dull can be sharpened, as long as it still can cut meat, even if it can only do so with some difficulty. Rashi explains that if it can no longer cut at all, sharpening it would involve serious labor that should not be done on the holiday. The Ba’al ha-Ma’or argues that such a knife no longer serves its purpose, and is therefore no longer considered a utensil. Sharpening it would create a new utensil on Yom Tov, which is certainly forbidden.
Another question that is raised is whether the shohet can present his knife to the community rabbi on Yom Tov. The Gemara records a disagreement in this case between Rav Mari brei d’Rav Bizna, who permits it, and the Rabbanan, who forbid it.
The obligation for the shohet who slaughters animals for the community to show his knife to the local scholar is a Rabbinic ordinance instituted both to ensure that kashrut is scrupulously kept and to honor the community rabbi. This tradition came to an end many years ago. Although during Talmudic times any individual could perform Sheḥiṭa, later on only professionals who studied the laws carefully were allowed to do it and were certified by the community Rabbis as experts who no longer needed further approval. Nevertheless, in some communities – particularly Hassidic communities – this practice is still followed to this day.
Regarding the discussion in our Gemara, the R”if explains that we may forbid the scholar to check knives on Yom Tov because we fear that the knife will be carried outside the 2000-cubit city limit. According to the Re’ah, the problem is that the scholar checking the knife plays the role of a judge, and courts are not allowed to operate on Yom Tov. The Rambam’s explanation is that if the knife is found to have a nick, the shohet may come to sharpen it, which is, as we learned in the Mishna, forbidden.