Wow.... good topic. Good points, but come on seriously?
There are good points about a tractor being like a battery cage, I do see your point. But a lot of other points I'm a bit leery of... this is just one...
What I'm saying is that a chicken tractor reminds me of a big, moveable battery cage. At least in a factory farm a chicken could walk 100 feet in a straight line if it wanted to.
20,000 chickens wouldn't be considered a barrier? What exactly would allow a chicken in this photo to walk a straight line from one end of the barn to the other?
It's physically impossible for one single chicken to walk to one end of the barn to the other. Since there are feeders and waters every 10 feet or so... there is no reason for them to wander that far any ways.
You could probably make the argument that tractors are worse then "yarding" chickens. It's a lot more arguable, and for one ...if you would make this argument you would be comparing apples to apples... instead of apples to oranges. As chickens that are raised outdoors get great ventilation, deal with the weather, get fresh grass, sunshine, plenty of bugs, ect.
But when you deal with commercial vs tractors, it's not even close. Stocking densities you could argue.... not very much of anything else. They aren't even comparable in my opinion, and it looks to be the majority opinion on this topic.
But just like your free range set up you control the stocking densities. However you may put it, your electric netting is like a big giant cage as well. You could easily fill your pen up with 4 times as much chickens/ducks if you wanted. But you don't, neither do I with my tractors. It's the same concept, just bigger. You contradict your own statements as you practice the same concept as I do, the only difference is... you use netting I use a tractor. A true free range setting would allow chickens/ducks to have access to about 5 acres of pasture 24/7. Not a 300 ft circle of netting.... (trust me... I'm with ya I use the netting for my layers).
Now to your main point.... as it is about money. For me to raise chickens to sell to the public and do it less than $3.00-$4.00 / lb I have to raise them in the tractors. Why? Well, part of the reason why the price is so high on home grown chicken is that it isn't done in any quantity. Meaning that there is very little money being made so to justify raising them... the price is $4.00 / lb. If I raise them in tractors, I control how much manure is put down on the pasture. Again, if you want any kind of quantity this is the key to your success. An overload of manure will make you have a brown pasture. Since you have to raise thousands to make a good profit and to keep prices lower so average people can afford it, tractors are the answer until another method is invented.
I could easily do it your way, and quite frankly it would be great as I would spend a fraction of the time taking care of them. Tractor farming is not an easy way to farm chickens, it's also not for the lazy farmer. To be honest, your very tuned in with nature and the natural flow of things. You move the pens based on weather, the more it rains, the less you have to move the pens. However if we are in drought conditions, I find myself moving pens 4 sometimes 5 times a day to make sure that I have pasture a month from then. Also the densities have a major role in your success. I do want you to understand that a true pasture poultry producer that does it for a living instead of feeding their family as different outlooks on the densities of the tractors. The higher the density the more you must move the pen, the less grass they get, and the less bugs they get. All of this makes for a bird that doesn't preform well and plays a disaster on your pasture. Most of the tractors you probably have seen was from people that only raise them once or twice. So the logic is who cares if the pasture burns out... "it has all summer to come back before my fall batch" Mine and many other producers are much different, it's more like your "yarding" farming. The less birds in a tractor, the more I can get from the pasture. And because this is based on quality not just quantity I must make sure that the pasture is very well maintained.
There are pros and cons about tractors no doubt... but their also is with your netting.... I happen to use both and like both. But honesty I can't justify the use of the netting for the broilers as I lose a bit of quality when I do. As you know broilers aren't as aggressive foragers, I find that they produce better when the forage is brought to them.
However please tell me what is so sad about my battery cages? I do see some of your points but you have to see some of mine too... right? There is a middle ground between commercial farming and "traditional" farming.