Modern animal husbandry is a marvel of technology. From instruments that guarantee the impregnation of animals to machines that milk dairy cows and the disassembly line that is the modern slaughterhouse, technology has relentlessly squeezed the resource requirements for livestock production. Writes James McWilliams,
"The efficiency of an industrial slaughterhouse, macabre as it may be, is a spectacle to behold. A farm animal entering the front door will reach the exit about 19 minutes later. It will do so not only as chops destined for the meat counter, but as pelts bound for Turkey, lungs sent to dog-treat manufacturers, bile for the pharmaceutical industry, caul fat (the lining of organs) for Native American communities, and liver destined for Saudi Arabia (which, go figure, distributes cow liver globally)."
But among all these technologies, the Confined Animal Feeding Operations (CAFOs) or “factory farms” stand out for their relentless efficiencies of production. Can you imagine being actually thankful for factory farms, those “gulags of despair” where modern animal husbandry has been conducted in such deplorable conditions? Knowing that factory farms are universally unloved, some have claimed that if only animal husbandry could be conducted differently through rotational grazing or some such "improved intensification” technique, Animal Agriculture could become sustainable. But the fact is that the mimicry of complex, bio-diverse ecosystems is difficult to achieve with just a few species: cows, humans, chickens and grass, especially when all these species are invasive in most places on Earth. When their biomass is constantly removed from land and consumed and excreted elsewhere, the nutrients on that land get depleted. Further, if animal husbandry is conducted within native bio-diverse ecosystems, then its impact on planetary boundaries would actually be far worse than with the factory farmed versions! This fact was vividly illustrated to me during a visit to the Zulu Nyala safari in South Africa, after attending the UN COP-17 Climate Change meeting in Durban in 2011.
The Zulu Nyala safari is situated on 5000 acres of lush green African land and it was completely encircled with an electric fence to create a somewhat closed ecosystem. On these 5000 acres lived over 1100 herbivores, including 380 impalas (deer), 250 Nyalas (deer), giraffes, wild boars, rhinos and elephants. In addition, there were exactly 7 carnivores, all of them cheetahs.
There were two cheetah brothers, a mother cheetah and her four 8-month old cubs. The two cheetah brothers were always found together, since one had a broken leg and couldn't hunt. Therefore, his brother used to hunt for the both of them. During all our Jeep treks, we would always find these cheetah brothers near the Eastern border of the safari because they were part of a litter of four and their two sisters were sold to the neighboring safari.
Our game warden, Jabulani Tembe, told us that the four cheetah cubs would be removed from the safari as soon as they reached their first birthday because the safari could not really support 7 cheetahs. This is because between them, these 7 cheetahs were consuming the equivalent of 1 whole deer each day. The Safari couldn't sustain the killing of 365 deer each year, since the deer do not reproduce fast enough to replenish such a kill rate.
Therefore, 5000 acres of lush green land in Africa could support over 1100 herbivores and exactly 3 cheetahs, on a sustained basis. Such is the arithmetic of land use requirement for supporting herbivores vs. carnivores in a truly bio-diverse, natural ecosystem.
If the cheetahs became human-like tinkerers of Nature and chose to engineer an ecosystem that maximized the production of food for them, they would
1) Remove all other herbivores on the safari, leaving only deer, since the cheetahs don't or can't eat the other animals,
2) Cull all deer as soon as their initial growth spurt is over so that the efficiency of conversion from plant foods to deer flesh is maximized,
3) Keep the deer imprisoned and stationary in order to minimize the food energy that the deer expend in locomotion and maximize the food energy converted to muscle mass,
4) Institute a fossil-fuel based mechanical system to transport the plant food to the enslaved, stationary deer,
5) Institute a controlled impregnation program on the female deer population,
6) Institute a recycling program to process all left over deer carcasses into protein meal for the live deer and finally,
7) Inject the deer with antibiotics and hormones to enhance their growth of muscle mass.
The result would resemble the factory farms of modern animal husbandry. If we reverse the efficiency gains achieved in each of these seven steps and revert to "humane animal husbandry," wouldn’t the land use requirement for the Animal Agriculture industry actually increase? Indeed, if we consider the enormous footprint of cheetahs in the wild, one cheetah supported on every 1700 acres, it is truly a prodigious engineering achievement on part of the Animal Agriculture industry to churn out so much animal-based foods for their billions of customers using just 45% of the land area of the planet! This works out to an average of just over 2 acres per person for a population of 7.4 billion people, 850 times less than what is required for cheetahs in the wild at the Zulu Nyala Safari!
But of course, just the top one-third of humanity is doing most of that consumption of animal foods, while the bottom 1 billion people are literally starving. Cheetahs are 100% obligate carnivores, unlike humans. Nevertheless, it is hard not to admire the accomplishments of the food scientists in the Animal Agriculture industry from an engineering standpoint. If not for all the hormones and the antibiotics to promote rapid muscle growth, the genetic selection that singled out the fastest growing animals and other ingenious technologies that these food scientists have deployed, all the forests in the world would probably have been completely destroyed by now. In our Butterfly phase, we would have had a much more difficult, if not impossible, healing job to do.
It is due to the enormous production efficiencies built into modern animal husbandry that it is still possible to restore much of the biodiversity of the planet, as was accomplished at the SAI sanctuary. Recently, scientists from the University of Arkansas pointed out that if human babies grew at the exact same rate as broiler chickens in the poultry industry do today, a 2 month-old human baby would routinely weigh 300kgs or 660 lbs! But such a broiler chicken is growing at least six times more rapidly than a chicken in Nature, aided by the hormones, antibiotics and other chemical stimulants in the feed.
If we revert back to the bucolic ways of old, surely we would need 6 times the resources to raise the same biomass of chicken for human consumption?
 The quote is taken from James McWilliams blog, http://james-mcwilliams.com/?p=341
 As characterized by Philip Wollen in http://bit.ly/1JNlrZx
 This viewpoint was popularized by Alan Savory in his TED talk, http://bit.ly/1kI51ft .However, this has been repeatedly debunked, e.g., at http://slate.me/1cbRZuJ
 A chicken grown in 1940 took 14 weeks to maturity and could fly. A chicken grown today takes 6 weeks to maturity and can barely walk. http://bit.ly/1eVWLk2