no, dont feed either of them to your pacu. theres no need what so ever. while i dont doubt in the wild, a pacu would turn down a baby rodent that may fall into the water, its not something that normal, or their digestive systems are used to dealing with.
in the wild, from what ive read, they favor fruits and nuts that happen to fall into the water, with the occasional crustacean or shrimp mixed in.
i think the best foods for a pacu would be spirulina wafers and a regular, cheap cichlid pellet. you can add in grapes and other fruits too to keep pacu's nice and healthy.