Factory Feed Free meat & laying birds

[U_Stormcrow]

I think part of the issue is that for at least a generation we've talked about Animal Units or Animal Unit equivalents - and its so tempting to say my ground is rated at 1 AUE per acre, an acre is 1,000# cow, that's equivalent to between 100 and 200 chickens (based on weight), so I should be able to support my flock of [near that number] by turning them loose.

Then reality strikes.

The AUE definition seems to be "under intense management", rather than Mother Nature doing her thing. and as we've all seen from the feed threads, its very difficult to give a modern chicken an optimum diet from greens (which you have at least some say over, seasonally), but you really benefit from an animal protein source and you can't control the bugs. There is a lot of hope in the fully free range management plan.

 

[raingarden]

Copy that, but to make it more confusing, maybe the conversion from cattle to chickens should not be based on their weight alone.

Like you say, protein has to come into play. Chickens eat a diet of about 15% protein. Good pasture will provide cattle about 1% protein in their diet. Fertilization can increase the biiomass and the protein content of the forage

Also, chickens eat about 3.5 to 4% of their body weight per day. Cattle eat about 2 to 2.5% of their body weight per day.

This one seemed counterintuitive to me, but google said that chickens burn about 200 kcal per pound of body weight per day while cows burn about 430 kcal per pound of body weigth per day.

I suspect the only way to determine the carrying capacity is to start low and keep increasing the number of birds until it doesn't work any more. I cannot do that because we're not fenced and cannot control outward migration to greener pastures.

 

[U_Stormcrow]

The "one size fits all" method of AUEs seems like a government solution (and probably is), where a useful number originally intended to give some estimate of the carrying capacity for cattle in the US west got "adapted" to unintended and ill suited purposes. But you can't kick a proverbial rock across the field of an AUE Google search without being given paragraph after paragraph, chart after chart for converting AUE to different livestock - horses, pigs, chickens, goats, etc. I've even seen the concept baked into zoning laws!

 

[Shadrach]

From what I can tell, fully free range chickens need about 5,000 square feet per bird on fairly productive ground without predators. They will still need some supplemental feed because without it the birds will be impossible to control and manage. I'm curious if others think this figure is in the ball park? BYC has all sorts of rule-of-thumb numbers and specificaions to go by.but not one for free-range carring capacity.

A couple of the studies I've read suggest that Jungle Fowl claim about an acre (43569 square feet) of territory per tribe.

Of course, there is a world of difference between Jungle Fowl and high production breeds.
The tribes I cared for in Catalonia took about an acre of territory per tribe but they got commercial feed as well as what they foraged. The amount of commercial they ate varied with the seasons and the weather conditions.
The nutrition demands for hens that lay say 250 eggs a year are nothing like those for a hen that may lay 30 eggs a year.
I think that the breed of chicken and it's provenance makes as much difference as does the amount of space they have to forage and the condition of that forage.

 

[Geena]

cows burn about 430 kcal per pound of body weigth per day.

Yeah, something is off there... a 1,000 steer would need 430,000 calories a day?
A pound of hay contains aprox 850 calories, so a 1,000 steer would have to eat about 500 lbs of hay a day?

 

[U_Stormcrow]

Yeah, something is off there... a 1,000 steer would need 430,000 calories a day?
A pound of hay contains aprox 850 calories, so a 1,000 steer would have to eat about 500 lbs of hay a day?

Its too early for commas. Let me get a cup of coffee first????

 

[Geena]

Its too early for commas. Let me get a cup of coffee first????

Please do, I'm not so great at math

 

[Shadrach]

Even if you had 1000 chickens based from one chicken house and able to free range unlimited amounts of space and range unlimited distances, they would completely ruin the ground around the coop to a certain radial distance and they would probably ruin a few big spots beyond that as well, because they are, well, chickens so of course they flock together, and have cliques, and dust in certain areas every day, roost in the same spot every night, etc.

One might have thought this would be the case but what I found with free rangers was they tended not to stay close to the coop and the ground around the coops remained relatively untouched.

 

[Shadrach]

Please do, I'm not so great at math

Nor me and I've got a degree in it.

 

[U_Stormcrow]

One might have thought this would be the case but what I found with free rangers was they tended not to stay close to the coop and the ground around the coops remained relatively untouched.

Mine too - yes, they have little pits they've dug - favored dustbathing spots under particular bushes, and next to a building, but in the main, the run and surrounds are recovering - I even have grass growing in the run again, and had to start pulling weeds!

Admittedly, my stocking density is quite low - but the only really barren areas are the paths I walk, and which my animals (chickens, ducks, goats) tend to follow.