Tossefta sur Le Lévitique 16:10

Rabbi Shimon says, wherever the Torah says "calf" without any modifier (סתם), [it means] a one year-old, [as it is said] (Lev. 9:3), "and a calf and a lamb, [each] one year old." [Wherever it says] "a young of the herd," [it means] a two year-old, as it is said (Lev. 9:2), "Take for yourself a calf, a young of the heard, as a sin-offering, and a ram as a burnt-offering, temimim." Temimim [means] "whole" as to years, and "whole" from any blemish. Rabbi Yosei says, three atonements are effected from bulls, and three from rams, and three from goats. And the three from bulls: The bull that is brought for the [unwitting transgression of] any of the commandments (Lev. 4:2-4:3), the bull of Yom Kippur (Lev. 16:6), and the the calf whose neck is broken (Deut. 21:6). The three from rams: The certain guilt-offering and the suspended guilt-offering (Lev. 5:15-19), and the lamb brought by the individual (Lev. 4:32). The three from goats: The goat of the pilgrimage festivals (Num. 28:22-29:38), the goat of Yom Kippur (Lev. 16:10), and the goat of the "prince" (i.e., a euphemism for Azazel) (see Ramban to Lev. 16:8).

[If] the goat to be sent away died before the blood of the first [goat] was sprinkled, even though [the High Priest] did not confess on it, he fulfilled [his obligation], as it is said (Lev. 16:10): "[The goat ... shall be left] standing alive." Until when must it remain alive? Until he has finished the atonement of the Holy (see Lev. 16:20), the words of Rabbi Yehuda. Rabbi Shimon says, until the time of the confession.