Alms Tax: Sheep Between Two Nisabs
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1929
Giving zakat is not obligatory on the number of sheep between two niṣābs. Therefore, if the number of sheep that a person owns is more than the first niṣāb, which is forty sheep, but it does not reach the second niṣāb, which is 121 sheep, he must give zakat on only forty sheep, not on more than that. The same applies to all the other niṣābs.
-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)