Musannaf Ibn Abi Shayba 5:134

Muhammad ibn Bakr narrated to us, from Ibn Jurayj, from Sulayman ibn Musa, who said: When the cattle reach thirty, then in them is a *tabi'* (a one-year-old calf) or a *jadha'* (a two-year-old male calf) or a *jadha'ah* (a two-year-old female calf), until they reach forty. Then, when they reach forty, in them is a *baqarah musinnah* (a mature cow).