Tosefta do Liczb 6:14

Israelites fulfill their obligation through vow offerings and freewill offerings, and with tithed animals. Kohanim [fulfill their obligation] through sin-offerings and guilt offerings, with first-born [livestock], and with breast and thigh [taken from peace offerings, see Lev. 9:21], but not from bird offerings and not from grain offerings. A Nazirite fulfills [his obligation] with his ram (see Num. 6:14), whether it belongs to him or whether it belongs to others, as long as he eats from the sacrifice all seven [days of the Festival].