Again, Managuense is a carnivourous specie, whom specialise in preying upon soft rayed fishes. Therefore, your Jaguar too (although captive bred and reared), is geneticly programmed to do so. Where as the other species mentioned are omnivourous, preferring other such meaty foods as mentioned, with a large amount of vegetable matter included.
I certainly wouldn't suggest feeder fishes to be lacking in nutritional value, yet they could, indeed, be carrying potentialy deadly parasites and what not. When including feeders (of any description) in the cichlids diet, i suggest doing so only on rare occassions. And that they undergo a lengthy period of quaranteen, along with a high quality diet and frequent, large volume water changes.