How long is a Yisrael required to care for a bechor? With small livestock, until thirty days; and with large livestock, fifty days. R’ Yose says: With small [livestock] three months. [If] the Kohen said to him within this time, “Give it to me,” he may not give it to him. [If] it was blemished, [and] he said to him, “Give it to me so that I may eat it,” it is permissible. However, during the era of the Temple, if it was perfect [and] he said to him, “Give it to me that I may offer it,” it is permissible.  The bechor must be eaten within the year, whether it is perfect or blemished, as it is said (Deut. 15:20): “Before HASHEM your God you shall eat it year by year.”

[If] it developed a blemish during its [first] year, it is permissible to keep it for the entire twelve months; after its [first] year, he may keep it only until thirty days.

[If] one slaughters a bechor and [then] shows its blemish —- R’ Yehudah permits [it]; R’ Meir [however] says: Since it was slaughtered without the sanction of an expert, it is forbidden.

[If] one who is not an expert inspected a bechor, and it was slaughtered by his sanction —- it must be buried, and he must make restitution from his property.  [If] one derived a verdict [and] he declared the guilty party innocent, or he declared the innocent party guilty, [or] he declared [something] tamei which was [in fact] tahor, or he declared [something] tahor which was [in fact] tamei —- what he has done is done, and he must make restitution from his own property. But if he was an expert approved by the court, he is exempt from making restitution. It happened that a cow’s womb had been removed, and R’ Tarfon had it fed to dogs, and the case came before the Sages, who declared it permissible. Todos the physician said: Not a cow or sow leaves Alexandria until its womb is cut away, in order that it should not give birth. Said R’ Tarfon, “Your donkey has departed, Tarfon!” R’ Akiva said to him, “R’ Tarfon, you are exempt, for you are an expert approved by the court, and any expert approved by the court is exempt from making restitution.”