Related for Beitzah 12:7

If an egg is laid on the holiday, others say in the name of Rabbi Eliezer: It shall be eaten together with its mother. If a calf is born on the holiday, it is permitted to slaughter it on the holiday because it permits itself. If a brood hatched on the holiday, it is permitted to slaughter it on the holiday because it permits itself.

An egg that was laid on Yom Tov: Others said in the name of Rabbi Eliezer [that] both it and its mother may be eaten [on Yom Tov]. A calf that was born on Yom Tov: It is permitted to slaughter it on Yom Tov because it renders itself permitted. A chick that hatches on Yom Tov: It is permitted to slaughter it on Yom Tov because it renders itself permitted.