What is the ruling on using animal protein sources such as "feathers, internal organs, carrion, and blood" in animal feed, given that some of these may be mixed with human sewage waste and carrion from imported sources?

The ruling on using impure substances in feed requires elaboration: if these substances have transformed and changed from their previous description, and no trace of the impurity remains in them, then the preponderant opinion is that it is permissible to use them as feed. Otherwise, it is not. However, it is better to avoid this type of feed.