Zuhayr (may Allah have mercy on him) narrates from Sayyiduna Ali (may Allah be pleased with him); he said: I think it is from the Prophet (peace and blessings be upon him), that he said: "Bring a quarter of the tenth ('ushr)." Then he narrated the hadith up to: "And on camels," and then he mentioned their zakah just as al-Zuhri (may Allah have mercy on him) mentioned it: On twenty-five camels there are five goats. When there is one more, there is a bint makhad. If there is no bint makhad, then a male ibn labun, up to thirty-five. Then he narrated the hadith: When there is one more, meaning over ninety, there are two hiqqahs fit to receive the stud camel, and this is up to one hundred and twenty. If the camels are more than that, then on every fifty a hiqqah.
It does not contain what is in the narration of Sufyan from Abu Ishaq about starting afresh. In it, and in many of the narrations from him, there is 'on twenty-five, five goats', and they have unanimously abandoned holding that view, because Asim bin Damrah and al-Harith al-A'war, narrating from Ali, contradict the well-known narrations about zakah from the Prophet (peace and blessings be upon him) and from Abu Bakr and Umar (may Allah be pleased with them both) on that point. Likewise, the narration of whoever narrated starting afresh from him contradicts those well-known narrations, besides the discrepancy and error within it itself, and the leading imams of transmission criticised it; so it must be abandoned in favour of what is stronger than it. And success is from Allah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7267