Chicken, being leaner, may be a more efficient protein source. For raw calories, I think beef would be more efficient.
Plus fat is a better calorie source than protein.
I edited my comment, but I think there are other factors, however in general Beef is very inefficient, even if per pound it is more efficient in providing energy, it's inefficient in producing that energy.
That is while Beef, pound for pound, might be more efficient for humans to consume, it isn't as efficient in producing that amount of amount in the first place, and requires more energy input than chicken meat.
The conversion ratio would hold if they ate the same things. Cows can survive on grass, which is often plentiful. Chickens more so on grains, which are harder to come by.
Having raised chickens when I was a kid, I can tell you that chickens will survive on almost anything organic. They're like little organic waste disposal units. There is a reason that no plants grow where chickens are kept in pens: they eat anything that grows. They'll eat any bugs they can find. I've also seen them eat other chickens that had died of some natural cause.
Chickens usually get fed grain because grain is cheap and plentiful and easy to dispense, but if you give them enough room to roam and vegetation to eat, they will eat it.
We used to throw all our food scraps (bit of bread, fruit, vegetable peelings) in a container and throw it to the chickens at the end of the day. They loved it, and would eat it all. We'd also collect rotting fruit from under the fruit trees and throw it to them. It would all get eaten. I found that pretty much the only thing chickens wouldn't eat were peach pits. Peach pits are way too hard, I guess.
In winter when we didn't have as much of a garden, we'd also let the chickens out of their pen. They'd happily roam around the yard, eating grass and whatever tasty bugs they can find. In the evening, they'd return to their chicken house in their pen and go to sleep. Very convenient.
I've come to the conclusion that chickens would happily eat us if they were large enough.
I believe that chickens are very efficient to raise. If you have enough vegetation around, you don't need to feed them at all.
"We used to throw all our food scraps (bit of bread, fruit, vegetable peelings) in a container and throw it to the chickens at the end of the day. They loved it, and would eat it all."
This cannot be overemphasized. You can very efficiently dispose of all of your kitchen waste (minus banana peels) by throwing them at the chickens who will turn them into eggs.
In fact, years ago when we first started keeping chickens, there was a period where I would see food waste at cafes and restaurants and be seriously tempted to pack it up and take it home because, after all, I could turn this into eggs.
> I've always thought that chickens, the free ranging kind, make insect protein palatable to humans.
In many parts of the world, certain insect protein is already palatable. To mention a few palatable insects I know of: the caterpillar stage of a specific moth species (Gonimbrasia belina)[1], locusts, termites[2] and - believe it or not - stinkbugs![3]
2. capturing soldier termites is a fun, albeit occasionally painful experience for kids. Those giant mandibles can cut skin, and once closed, they never open
>In the evening, they'd return to their chicken house in their pen and go to sleep.
>If you have enough vegetation around, you don't need to feed them at all.
These two things are why you frequently see free roaming chickens in villages in poor parts of the world. They don't need feeding and minimal care or supervision is required.
In a rural setting whether there is plenty of vegetation available and few predators chickens are very close to being free egg and meat producing machines as there is virtually zero time or money required from their owners.
Why would you think that? Larger animals are usually much more energy efficient for various reasons - less surface area to radiate heat, and economies of scale with larger organs.
I believe you, but I'm very surprised. That has larger animals almost universally less efficient than smaller animals, which is the exact opposite of the expected efficiency due to Kleiber's law: https://en.wikipedia.org/wiki/Kleiber%27s_law
>a cat, having a mass 100 times that of a mouse, will have a metabolism roughly 32 times greater than that of a mouse.
And yet this is saying that a mice sized animal should be expected to have the same, or perhaps even better Feed conversion ratio than a cat sized animal.
The larger livestock will usually have a much longer lifespan. It has to keep its flesh heated above ambient for that entire lifespan. If Mouse A lives 100x longer and puts on the same weight and achieves the same stature as Mouse B, it's spent ~100x as much energy getting to the same physiological place as Mouse B.
Cows are slaughtered at 80 weeks while chickens are slaughtered at 6 - 8 weeks. That extra order of magnitude of basal metabolic rate is where the energy gets consumed.
Not really. There's a basic thermodynamic inefficiency as organisms get larger, and consume farther away from the energy source, in this that being the sun.
A little quick googling and I found: https://en.wikipedia.org/wiki/Feed_conversion_ratio