I've been reading a bit on captive king cobra husbandry, and I notice that many venomous keepers heavily argue and debate about whether to feed king cobras rodents or snakes (hence their wild diet consists mostly of snakes). I'm already aware hatchling king cobras eat snakes, but some people choose to transition their kings to mice/rats, while others say that rodents are fattening to kings themselves (since they're higher with fat). However, many accredited zoos and some keepers have fed king cobras exclusively rodents without any ill effects. Any opinions on this case?
My understanding is that transitioning king cobras to eating rodents is a common husbandry practice; feeder snakes are a lot more expensive and hard to come by. It's better to transition them when they're young, snakes are very habit-forming and transitioning them to other food sources once they become adults is usually difficult and sometimes impossible. It should be noted as well that snakes are just the primary diet of king cobras; they do eat rodents and birds in the wild, especially when other snakes are scarce.
It would be interesting to compare the microbial gut flora of a) wild king cobras (in different areas of their distribution), b) captive (born & raised) king cobras fed solely on snakes (i.e. corn snakes and ball pythons, which isn't an all too diverse diet either and carries along the spread of Cryptosporidium serpentis) and c) captive (b&r) king cobras fed solely on rodents. I dare to predict that the microbial diversity of Option a) will be greater than that of the other options, but as long as the specimens do well and breed in capivity *shrugs*.
Is the Entamoeba invadens also significant pathogen in captive reptile husbandry, and that can be transmitted in such a way (via snake diet for king cobra)?
@Nikola Chavkosk: it still is, but not to the grand scale it used to be (at least in my experience). The problem with Cryptosporidium serpentis is that some strains of corn snakes and ball pythons are particularily susceptible to it, thus increasing the chance of transmitting it to ophiophagous snakes. So if you have said snakes and want to play it safe, having your own controlled breeding colony of feed snakes or using another kind of prey item might be a good idea. You just have to be careful that the prey doesn't try to eat the predator...^^ Predator Becomes Prey | The Reptile Report
There's some king cobra keepers out there who believe that rats are terrible for king cobras but I haven't found a research paper that has said so :/