Beis Shammai say: A Yisrael may not be invited [to join] with a Kohen in a bechor. Beis Hillel [however] permit [it], and even a non-Jew.  [If] a bechor suffers from a congestion of blood, even if it will die it may not be bled; [these are] the words of R’ Yehudah. The Sages [however] say: He may let [its] blood, provided he does not inflict a blemish upon it; and if he did inflict a blemish upon it, it may not be slaughtered on its account. R’ Shimon says: He may bleed it even though he inflicts a blemish upon it.

[If] one slits the ear of a bechor, it may never be slaughtered; [these are] the words of R’ Eliezer. The Sages [however,] say: When it develops another blemish, he may slaughter it on its account. It happened with an old ram with dangling hair [that] a questor spotted it. He said, “What is the reason for this?” They said to him, “It is a bechor, and it may not be slaughtered unless it has a blemish”; [whereupon] he took a dagger and slit its ear. The matter came before the Sages, and they permitted it. [When] he saw that they had permitted [it], he went and split the ears of other bechoros, and they prohibited [it]. Once children were playing in the field, and they tied the tail of lambs one to another. The tail of one of them was torn off, and it was found to be a bechor. The matter came before the Sages, and they permitted it. [When] they saw that they had permitted [it], they went and tied together the tails of other bechoros, and they prohibited [it]. This is a rule: Whatever is [done] with knowledge is prohibited, and without knowledge is permissible.

[If] a bechor was pursuing him, and he kicked it and inflicted a blemish upon it, he may slaughter on account of it. [For] all blemishes that can be inflicted by man, shepherds [who are] Yisraelim are believed, but shepherds [who are] Kohanim are not believed. Rabban Shimon ben Gamliel says: He is believed concerning his friend’s [bechor], but he is not believed concerning his own. R’ Meir says: One who is suspected concerning a thing may neither judge nor testify about it.

A Kohen is believed to say, “I showed this bechor [to an expert] and it is blemished.” All are believed concerning the blemishes of the maaser [offering]. [If] a bechor’s eye was blinded, its foreleg cut off, [or] its hind leg broken, it may be slaughtered by the decision of three laymen. R’ Yose says: Even if there are twenty-three, [it] may not be slaughtered except by the decision of an expert.

[If] one slaughters a bechor and sells it, and it becomes known that he did not show it [to an expert], what they ate, they ate, and he must return their money to them; and whatever meat they did not eat must be buried, and he must return the money to them. Similarly, [if] one slaughters a cow and sells it, and it becomes known that it was a tereifah, what they ate, they ate, and [he] must return the money to them; and whatever meat they did not eat they return to him, and he must return the money to them. [If] they sold it to non-Jews or gave it to dogs, they must pay him [only] the worth of a tereifah.

On account of the following blemishes a bechor may be slaughtered: Its ear is notched in the cartilage, not in the skin; [or] it is slit, although nothing is missing; [or] it has a hole as big as a vetch; or it has dried up. What is considered dried up? Anything that, if punctured, does not emit a drop of blood. R’ Yose ben Meshullam says: It is so dry that it crumbles.

An eyelid that is punctured, notched, or slit, [or] there is a cataract in its eyes, [or] a commingling, [or] a snail-shaped, snakelike [growth], or a berry-shaped growth.  What is a commingling? The white breaks through the ring and enters the black. [But if the commingling] is in the black and enters the white, it is not a blemish, for there are no blemishes in the white.

White flecks or water that are permanent. What are permanent white flecks? Any that remained eighty days. R’ Chanina ben Antignos says: We examine it three times within eighty days. What is permanent water? [If] it ate fresh and dry [fodder] from a rain[-watered field]. [But if it ate] fresh and dry [fodder] from an irrigated field, [or] if it ate dry [fodder] and afterward ate fresh [fodder], it is not [considered] a blemish, unless it eats the dry after the fresh.

Its nose is punctured, notched, or slit; [or] its lip is punctured, notched, or slit; [or] its front teeth are notched or worn down, or its back teeth are uprooted. R’ Chanina ben Antignos says: We do not examine behind the molars, nor the molars themselves.

The sheath of the male organ is notched, or the genitals of a female in consecrated animals; the tail is notched in the bone, but not in the joint, or if the tip of the tail was exposed to the bone, or if there is a fingersbreadth of flesh between the joints [of the tail].

It does not have testicles, or it has only one testicle. R’ Yishmael says: If it has two pouches, it has two testicles; [if] it has only one pouch, it has only one testicle. R’ Akiva says: It should be set on its buttock and squeezed; if there is a testicle there, it will eventually emerge. It once happened that they squeezed it and it did not emerge, and it was slaughtered, and it was found attached to the loins, and R’ Akiva permitted it, but R’ Yochanan ben Nuri prohibited it.

It is five-legged or it has only three; or its feet are round like that of a donkey; and the shachul and the kassul. What is a shachul? One whose hip is dislocated. And a kassul? [An animal] whose one hip is higher [than the other].

The bone of its foreleg, or the bone of its hind leg, was broken, although it is not discernible.  The aforementioned blemishes were enumerated by Ayala in Yavneh, and the Sages concurred with him. He [also] added another three; [but] they said to him: We have not heard of these.  [These are:] The circle of its eye is round like that of a man, or its mouth resembles that of a pig, or the greater part of its fore-tongue is gone. However, a subsequent beis din said: These are [indeed] blemishes.