Regarding the Nisaab level or cattle or livestock?

Answer By Dr Zakir Naik,As far as animal is concerned only those animals that are used for grazing that freely graze and you don't have to feed them though, no one has to feed them like camels, cows, goat, sheep on them Zakaat is liable. For other animals where the owner has to feed them with hay like horse etc., for them Zakaat is not liable but natural if its sold and if the money is used and if the money is kept and if it reaches above Nisaab level, if it's kept with you for one year them Zakaat is liable. But generally directly Zakaat is only on the cattle, camel, cow, goat, sheep and the Nisaab level for camel is 5 camels, for the cow it is 30 and for goat and sheep it is 40 and there is a Hadith of Muhammad (Sallallahu alaihe wa sallam) its mentioned in
Sahih Bukhari vol. no. 2 in the Book of Zakaat Hadith no. 1454 that
"Hazrat Umar (may Allah be pleased with him), he said that he will take Zakaat from the people and he gives Allah's Messenger, he quotes him and says that he said that "for every 5 camels, one sheep should be given."
The Nisaab for the camel is 5, and for every 5 camels, 1 sheep should be given as Zakaat and as the camels keep on increasing the Zakaat keeps on changing, for the sheep once it reaches 40 then you have to give one sheep, below 40 there is no Zakaat. 40 is the Nisaab level for the sheep. If it reaches 40 then one sheep should be given. Between 40 and 120 it is one sheep. Between 120 and 200 sheep it is 2 sheep. Between 200 and 300 sheep it is 3 sheep and then additionally for every 100 sheep there is one sheep.