Musannaf Ibn Abi Shaybah

Hazrat Ali (may Allah be pleased with him) said that for forty to one hundred and twenty goats, the zakat is one goat, and when they exceed one hundred and twenty up to two hundred, then two goats; and when they exceed two hundred up to three hundred, then three goats; then when they exceed three hundred, for every hundred, one goat. Hazrat Abdullah also says the same, that up to three hundred. Then when they exceed three hundred up to four hundred, then four goats. Then zakat will be according to this calculation. The narrator of the hadith, Muhammad, says that Hazrat Amir told me that both Hazrat Ali (may Allah be pleased with him) and Hazrat Abdullah said that the separated should not be combined, and the combined should not be separated.