Question: 

Is it permissible to feed animals such as lions a cow that is alive, or in general, can any other animal be given live animals as their feed? What is the ruling when it comes to fishing with worms, etc? 

Answer: 

First and foremost, it is prohibited to punish, trouble, or distress any creation of Allah Ta'aala, be it Insaan (humankind) or any other Makhlooq (creation), it is against the spirit of Shariah.