[If] the hair of a blemished bechor fell out and he placed it in a recess in the wall, and afterward [he] slaughtered it —- Akavya ben Mahalalel permits [it], and the Sages prohibit [it]; [these are] the words of R’ Yehudah. R’ Yose [however] said: Not in this [case] did Akavya [alone] permit [it]. Rather [they argued about] the hair of a blemished bechor that fell out and was placed in a recess, and afterward [the animal] died —- in this [case], Akavya ben Mahalalel permits [it] and the Sages prohibit [it].  [If] wool is hanging from a bechor —- that which appears to be from the shearing is permissible; and that which does not appear to be from the shearing is prohibited.

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.”