[Taxacom] Cannibalistic offal (in nature); is such offal awful?

[Kenneth Kinman]

Hi All,
      Well, it seems the Salmonella contamination in those Iowa chickens
and their eggs has been traced to their feed.   I wouldn't be surprised
if that feed included "chicken offal meal", in which various discarded
body parts of chickens are reprocessed and fed back to other chickens,
thus forcing them into cannibalism.   
       I recall that BSE (mad-cow disease) may well have been the result
of feeding cow offal to other cows (and ultimately then to humans,
especially that deadly outbreak in Britain, and as I recall, perhaps
even some cannibals in New Guinea who relish human brain).  So, is
feeding the offal from the dead of the same species a good idea?  Or is
offal awful (dangerously unnatural) in such cases?  
      Anyway my question is this, are there cases in nature when species
often eat members of their own kind (cannibalism) without a negative
effect?   Some arachnids do so (spiders, praying mantises, etc.,
sometimes eating their mates), but they don't generally live very long
after doing so anyway, so no big deal), but what about long-lived
species that eat members of their own kind?  Lions kill cubs when they
take over a pride, but I don't think that they eat them.  However, do
scavengers that specialize in eating the dead, such as vultures and
hyaenas eat dead members of their own kind?      
             ------Ken Kinman
P.S.  As you might have guessed, I don't think that humans forcing their
domesticated animals into cannibalism is a good idea.  To me the idea of
cannibalistic offal is awful (and dangerous).  Such practice seems bad
for the animals themselves and potentially for anyone who might
ultimately eat them.  The only benefactors of such practices seem to be
the owners of large-scale (industrial) farming of animals.