1,016. A Blemished Firstborn Animal on Yom Tov

Shvisas Yom Tov 2:4

(A firstborn animal is automatically sanctified unless it is blemished.) If a firstborn animal is born on yom tov with a blemish, it is considered prepared for use and may be slaughtered but the blemish still may not be examined on yom tov. However, if one violated the law and had the blemish examined and the animal was ruled permitted, then one may slaughter and eat it on yom tov. If a firstborn animal falls into a pit on yom tov, one should feed it there. It is not permitted to raise the animal from the pit because it is not prepared for use on yom tov. (A mother animal and its child may not be slaughtered on the same day.) If a cow and its calf both fall into a pit on yom tov, one may be removed with the intention to slaughter it, and then one may refrain from slaughtering it. One may then remove the other animal with the intention to slaughter it, after which one slaughters whichever of the animals that he prefers. One is permitted to act disingenuously in this case in order to alleviate the animals’ suffering. If an unconsecrated animal fell off a roof and survived for an entire day, it must be examined before it may be eaten. However, the animal may be slaughtered on yom tov and then examined because of the possibility that it is kosher.

Shvisas Yom Tov 2:5

Ducks, chickens and doves in one's home are considered prepared for use on yom tov without special designation. Doves in a coop or a loft and birds that roost in buildings or orchards are muktzeh. If one wants to slaughter them on yom tov, he must designate them on the day before, saying, “I will take these and these.” He does not have to physically manipulate them.