Related sur Bikkurim 2:9

What is sourdough? Something that leavens other things. And what is leavened? Something that has been leavened by other things. From when is it called sourdough? As soon as it become unsuitable as dog food. One must not cover blood with ashes which burned [and thus created] during the holiday, because it does not count as something "prepared [before the holiday]". If one brought dust to plaster his roof, lime to whitewash his house, one uses it to cover. Rabbi Yose says: you can on a holiday not slaughter a koi because it is a doubt, and if one has slaughtered him, one does not cover his blood.

A k'vi (see Bikkurim 2:8) -- how is it like a wild animal? Its blood requires covering like a wild animal. Rabbi Eliezer says, they are liable to bring a variable guilt-offering for [partaking in] their [forbidden] fats. How is it like both a wild animal and a domesticated animal? One who flays (המפשיט not מפסיד, see GR"A) it, [the laws regarding whether its hide is] connected [to its flesh is] like wild animals and domesticated animals (see Tos. Chullin 8:6). And [the laws of] the sciatic nerve apply to it, like they do to wild animals and domesticated animals. If he said, "Behold, I will become a nazirite if [the k'vi] is [neither] a wild animal or a domesticated animal," behold, he has become a nazirite. Rabbi Yosei says, a k'vi is a unique creation unto itself, and the Sages were unable to render a decision about it, if it it is a wild animal or a domesticated animal.