من لا يحضره الفقيه, volume 2, page 24

Hadith.1604 - Umar ibn Udhaynah narrated from Zurara, who reported from Abu Ja’far Imam Muhammad ibn Ali Al-Baqir (as) who said: "There is no Zakat on fewer than five camels. When there are five camels, one sheep is due as Zakat, up to ten camels. When there are ten camels, two sheep are due. When they reach fifteen camels, three sheep are due. When they reach twenty camels, four sheep are due. When they reach twenty-five camels, five sheep are due. If they exceed twenty-five camels by one, a yearling she-camel (bint makhad) is due, up to thirty-five camels. If the owner does not have a yearling she-camel, then a yearling male camel (ibn labun) is acceptable. When the camels exceed thirty-five by one, a two-year-old she-camel (bint labun) is due, up to forty-five camels. If they increase by one over forty-five, a three-year-old she-camel (hiqqah) is due. It is called hiqqah because it has become eligible to be ridden. This continues up to sixty camels. If they increase by one beyond sixty, a four-year-old she-camel (jadha'ah) is due, up to seventy-five camels. If they increase by one beyond seventy-five, two two-year-old she-camels (bint labun) are due, up to ninety camels. If they increase by one beyond ninety, two three-year-old she-camels (hiqqah) are due, up to one hundred and twenty camels. If they exceed one hundred and twenty camels, for every fifty camels, a three-year-old she-camel (hiqqah) is due, and for every forty camels, a two-year-old she-camel (bint labun) is due."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.