An aged animal or one with a defect1 must not be given as zakat.
For silver currency2, one-fortieth is due on two hundred dirhams. If there are only one hundred and ninety, no zakat is due unless the owner wishes to give voluntarily.
If a person’s camels reach the threshold at which a four-year-old she-camel is due, but he does not have one and instead has a three-year-old she-camel, the latter shall be accepted from him, together with two sheep, if he can readily provide them, or twenty dirhams.
If his camels reach the threshold at which a three-year-old she-camel is due, but he does not have one and instead has a four-year-old she-camel, the latter shall be accepted from him, and the zakat collector shall give him twenty dirhams or two sheep. Reported by al-Bukhārī3.
214- In the hadith of Mu'ādh, the Prophet (peace and blessings be upon him) instructed him to take, from every thirty head of cattle, a one-year-old male or female calf4, and from every forty, a two-year-old cow5. It was reported by the compilers of the Sunan collections6.