Creature wrote:
>>is there a reason why most/all food animals are naturally herbivorous?
>>i know people eat dogs in some countries, but are there any other
>>naturally carnivorous animals that are used for food?
>
> I'd say food chain issues make keeping carnivourous animals for food even
> more wasteful. Energy is lost, the further up the food chain you go -
> Feeding a cow a ton of veggies than eating it will give you less energy
> than eating the veggies yourself, as some of the energy in the veggies has
> gone into the cow moving, breathing, circulating blood etc. Feeding the
> cow to a dog, or a set of dogs, then eating the dogs gives you even less
> energy because the dogs will have used some of that energy too. This is
> stuff I remember from biology; there's probably something similar in place
> regarding nutrients.

That's a fair grasp of entropy, but grossly exaggerated since the energy
loss isn't as direct a comparison as you've explained it.

Cattle usually don't eat veggies, but silage, grains, legumes -- and
almost always stuff completely unsuitable for human consumption. Game
animals also rarely eat food intended for humans, unless they trespass
into someone's garden, orchard, etc. Pigs are often fed with scraps and
other non- and unconsumable (by humans) feed. Most poultry can also
convert stuff humans normally wouldn't eat.

Question: Take any of those animals out of the equation, and what's the
net gain/loss in the system?
Answer: A gain of usable protein for humans.