Numbers 7:87-88
7:87 All the animals for the burnt offering were 12 young bulls, 12 rams, 12 male lambs in their first year, with their grain offering, and 12 male goats for a purification offering.
7:88 All the animals for the sacrifice for the peace offering were 24 young bulls, 60 rams, 60 male goats, and 60 lambs in their first year. These were the dedication offerings for the altar after it was anointed.
Numbers 8:17
8:17 For all the firstborn males among the Israelites are mine, both humans and animals; when I destroyed all the firstborn in the land of Egypt I set them apart for myself.
Numbers 18:15
18:15 The firstborn of every womb which they present to the Lord, whether human or animal, will be yours. Nevertheless, the firstborn sons you must redeem, and the firstborn males of unclean animals you must redeem.
Numbers 31:47
31:47 From the Israelites’ share Moses took one of every fifty people and animals and gave them to the Levites who were responsible for the care of the Lord’s tabernacle, just as the Lord commanded Moses.