How big is a chicken's footprint?

I've been thinking about chickens a lot recently.

I would dearly love to raise my own chickens for eggs and meat. But if I raise chickens, I want to do so not just humanely (which is relatively easy), but also as sustainably as possible (which is a much bigger challenge).

Total sustainability implies a closed, self-supporting system that can operate indefinitely without taking inputs from elsewhere. A closed system would, for example, provide all of the nutrients and dietary supplements (including grit) that a chicken needs in order to be healthy and productive. It would also provide all housing materials.

Modern domestic chickens are the descendents of Red and Grey Junglefowl, which evolved in the tropical forests of Asia. Generally speaking, the further removed a chicken is from its native tropical forest environment, the more dependent it will be on its human keeper for food, shelter, and protection.

The first major problem I have with creating a sustainable chicken-raising operation is that my "system" (my land) is only two acres in size. So, the first question I asked myself, before eagerly rushing out to buy some chooks, was: how much land does one productive chicken need?

I may as well have asked myself: how long is a piece of string? The answer to the chicken question depends on a large number of variables, including: what is the local climate like? (Is the land bountiful? Is it prone to drought? Is it under snow for several months of the year?). And what exactly is a "productive" chicken, anyway? (Is it one that produces an egg every day? Or is it one that simply performs some basic weed control?) The questions go on, but I'm sure you get my drift.

So, I started Googling, and (as my favourite blogger noted at the time) I found a figure that has surprised everyone I've mentioned it to: the general consensus seems to be that a 100% free range chicken requires roughly half an acre of land in order to meet all of its requirements. 

Most of the people I've mentioned this "Chicken Footprint" to have responded with incredulity; even (or perhaps especially) the people who actually raise chickens - although I'm yet to meet a chicken owner who maintains even one healthy chicken without buying supplementary feed or additives of some description.

(As an interesting side note, some local friends mentioned that the monetary value of the chicken feed they buy actually exceeds the monetary value of the eggs they get from the half-dozen aging hens in their backyard).

Lierre Keith, author of The Vegetarian Myth, touches very briefly on the chicken footprint concept in Chapter 1 of her book. She writes:

I’ve heard vegetarian activists claims that an acre of land can only support two chickens. Joel Salatin, one of the High Priests of sustainable farming and someone who actually raises chickens, puts that figure at 250 an acre. Who do you believe?

Keith heavily implies that her readers should unquestioningly believe that one acre of land can sustainably support 250 chickens. Unfortunately, she provides no data or reference to support her belief. However, if she had bothered to read Joel Salatin's own book on the subject of raising pastured poultry, she would realise that her belief is, quite simply, wrong.

As an aside, it's interesting that Lierre Keith refers repeatedly to Joel Salatin as a "high priest". Unfortunately, her belief in Salatin's ability to squeeze truly miraculous levels of productivity out of one acre of land seems faith-based rather than fact-based. Maybe Salatin should capitalize on the religious-style fervour he stirs in people, and start a new cult:

Joel Salatin, the Messiah of Meat Lovers

As it happens, I own a copy of Salatin's book, Pastured Poultry Profits. The book (which is widely regarded as the best source of information about raising chickens on pasture) was first published in 1996, and was most recently updated in 1999.

The crux of the matter is this: "chickens cannot be totally grass-fed, according to several experts. They also need grain." (Ref: Chicken Feed)

Why can chickens not be totally grass fed? Because chickens are omnivores; they are not grazing, grass-eating, specialist herbivores. By contrast, sheep, cattle, and geese are physically adapted to thrive on a diet of 100% grass.

It is no coincidence that it is primarily omnivorous farm animals - pigs and chickens - who have ended up suffering the intensive confinement of factory farming. Why? Because pigs and chickens "destructively" dig up pastures in search of highly nutritious sub-surface critters and other goodies, such as roots.    

As it happens, even Joel Salatin's "pastured" chickens are mostly grain fed. According to Salatin, "the prepared ration represents 80 percent of the [pastured] bird's diet". He goes on to explain that 92% of the prepared ration he feeds his chickens is made up of annual grains, specifically:

Corn - 52%
Soy  - 29%
Oats - 11%

"So what?", you might ask.

The point is that, based on average US yields of corn, soy, and oats, you can't actually grow enough grain on one acre to feed 250 chickens (even assuming the chickens are getting 20% of their feed from pasture). And even if you could grow enough grain on one acre, where would those 250 chickens be living while you grow the grains to feed them (keeping in mind that corn, soy, and chickens all share the same spring and summer growing period)?

Following are the assumptions I used to calculate roughly how much grain it would take to feed Salatin's 250 Cornish Cross chickens for 6 months (which is how long Salatin raises broilers for each year).

The Cornish Cross is a large, fast-growing meat breed of chicken, which, in addition to fresh pasture, eats about 150g of feed per day (reference: Washington State University). Multiplied by 250 birds, that's 37.5kg of grain per day. Multiplied by 182 days (i.e. 6 months), that comes to a total of 6.8 tonnes of grain per year.

Broken down by grain (according to Salatin's feed mix), and using average US yield data, that's:

3.5 tonnes corn @ 4130kg/acre = 0.85 acre
2.0 tonnes soy @ 1188kg/acre = 1.68 acres
0.7 tonnes oats @ 1900kg/acre = 0.37 acres

TOTAL = 2.9 acres - just to grow the necessary grain to feed 250 birds for six months.

Then there's the acre of pasture that these chickens need to actually live on, bringing us up to 3.9 acres thus far, which equates to a substantially reduced figure of 64 birds per acre. If you subtract Salatin's average broiler mortality rate of 7.5%, you're down to 59 birds (Cornish Cross chickens are susceptible to having heart attacks late in the season, so you can't realistically expect to make a proportional saving in feed).

But that's not the end of the story by a long shot.

Salatin's super-productive system relies on the highly-controlled confinement and movement of (to use Salatin's words) "race car chickens". The Cornish Cross is a hybrid chicken which is "constantly being genetically upgraded by the commercial industry to perform at a totally unnatural gain rate" (also Salatin's words, ref: p.32). 

Salatin places his broilers in moveable pens which provide a space, on average, of less than two square feet per chicken. In this respect, it's worth noting that Salatin's broiler operation meets one of just two criteria which define a CAFO (a.k.a Concentrated Animal Feeding Operation, a.k.a a factory farm). Specifically: the animals are confined for at least 45 days in a 12-month period. 

Now consider some of the inputs, other than grain, that Salatin draws on to raise his pastured poultry (the following are all specifically mentioned in Salatin's book):

* live chicks from a commercial hatchery
* wood shavings for chick bedding (Salatin's chicks live on a floor of wood shavings for 12 to 28 days of their 56-day lifespan. Salatin raises multiple batches of chickens each season).
* artificial heat source to keep chicks warm
* drinking water
* feed and water containers
* hay chaff
* moveable pens (made from treated softwood, aluminum sheeting, chicken wire, screws, etc)
* plastic buckets (as Salatin says: "the world revolves around 5 gallon buckets")
* grit (creek sand and aggregate)
* feed grade limestone
* mineral supplements
* fish meal
* kelp meal (from Iceland)
* commercial probiotic
* cattle for keeping the pasture short before and after the chickens pass through
* tractor and fuel for transporting feed, water, and chickens.

Could anyone (besides Lierre Keith) seriously claim that all of these materials can be sourced sustainably from one acre of land? With room to spare for the actual pasture-fed chickens?

Furthermore, key factors that Joel Salatin's broiler system doesn't concern itself with at all are:

* Breeding: Salatin buys his chicks from a commercial hatchery. The poultry hatchery industry is a form of factory farming whose collective harm goes way beyond the scope of this blog post.

* Incubation: Salatin's system is based on artificial incubation, and the controlled confinement of all broilers, at all times.

* Winter care for birds: Salatin only keeps broilers for six months of each year, which is convenient for him, because Polyface Farm gets deep snow over winter. Chickens evolved in tropical jungle, so they don't cope well with snow. They certainly can't be expected to utilize fresh pasture for food during snowy winters. Hence, you would have to double the amount of land, or halve the number of chickens, in order to produce enough feed to keep the birds alive for an entire year. This brings us down to fewer than 30 birds per acre, or less than 12% of the stocking rate suggested by Lierre Keith - and that's still completely ignoring all of the inputs in the list above.

Having thought long and hard about this issue, I suspect that a chicken probably needs more than half an acre, assuming that your environmental accounting is unflinchingly honest (by which I mean that all inputs, including timber, fossil fuels, metal and plastic, as well as feed supplements such as fish meal, grit, and Icelandic kelp etc, are recorded in the ledger).

So. I think I can justify keeping a few chickens, even though creating a closed chicken-raising system on my two acres remains a pastoral fantasy. But, at the very least, I'm quite convinced that a pastured chook would have a happier life than a factory chook; and happiness counts, in my ledger.