Answer
Whatever animals are permissible to slaughter for Qurbaani is also
permissible for Aqeeqah. For a bull to be slaughtered, it has to be 2 years
old. If it is younger than 2 years, it will not be permissible for Aqeeqah.
(Aap ke masaail vol.4 pg.227)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai