Is it permissible to eat chicken that has been fed artificial feeds and drugs, even if it was slaughtered according to Islamic law?

If the artificial feeds or medicinal drugs designated for chicken nutrition do not contain any harmful or impure substance, then there is no objection to consuming chicken slaughtered according to Islamic law. However, if these substances are harmful to health, then it is forbidden to use them for chickens and to consume such chickens, due to Allah's saying: (And do not throw [yourselves] with your [own] hands into destruction) and the Prophet’s (peace be upon him) saying: (There shall be no harm or reciprocating harm).

If the feeds are impure, then the chicken may not be eaten unless the majority of its feed is pure. But if the majority of its feed is impurity (which is "jallalah" - animals that feed on filth), then it is not permissible to eat it until it has been confined and fed pure food for a sufficient period (such as three days) until the effect of the impurity is removed from its flesh.

Scholars have differed regarding the ruling on chickens that feed on impurities, and the preponderant view is the detailed one: if most of their feed is pure, then they are permissible. If most of their feed is impure ("jallalah"), then they are forbidden until they are confined and fed pure food. The prohibition is lifted once the effect of the impurity is removed.