Feature

Why are Livestock Livestock?

There is a reason why we don't often keep lions and polar bears as domesticated farm animals.

Lorne Kuehn

In the world at present there are 148 big, wild, terrestrial, herbivorous mammalian species. Only 14 have been domesticated as livestock, and some of these only poorly. Why has this happened, and what is it about these species that brought about their domestication?

This is a question of interest to those in saving rare breeds, as the answer might explain why some breeds are rarer than others.

It turns out that most of the candidate species are doomed to perpetual wildness and can never be tamed. To be tamed as livestock requires that the species possesses many complementary characteristics, all of which are required for success.

The first of these is diet. Whenever an animal eats plants or other animals, only about 10% of the energy in the food winds up as part of the consumer's body mass. It takes about 10,000 pounds of plant matter to make a 1,000-pound cow. Similarly, if you wanted a 1,000-pound carnivore, you would have to feed it 10,000 pounds of meat, which is equivalent to 100,000 pounds of plant mass.

This explains why no carnivore has been domesticated as human food -- it is just too inefficient to do it. The only minor exception is the dog, which is eaten in parts of Asia at present, and has been eaten in the past in Aztec Mexico, Polynesia and China. However, regular dog eating is considered by many anthropologists to be the last resort of meat-deprived human societies.

The second characteristic is growth rate. For efficiency, domesticated livestock must grow quickly. That is why potential livestock such as gorillas and elephants are not domesticated; they grow too slowly. Elephants are only reared by humans in small numbers for zoos as exotic exhibits. Work elephants are captured as adults rather than reared, as this is the much cheaper option.

Next comes the consideration of problems of captive breeding. Some mammalian species that you would think of as being very suitable for domestication turn out to be very finicky about having sex in the confines or proximity of humans. Two examples where this is a primary concern are cheetahs and Andean vicunas, both very desirable for domestication, the former for hunting and the latter for its exceptionally fine fleece. Both, however, have elaborate courtship procedures that can not be carried out in most enclosures.

This brings up the subject of nasty disposition or temperament. Although it is true that all large mammals, even pigs, horses, camels and cattle, can kill or injure humans, some are much more prone to do so than others. That is why we do not rear grizzly bears or Cape buffalo for food.

The worst animal in this context is the hippopotamus. It is very desirable for domestication, since it weighs four tons, but it is so nasty that it kills more humans in Africa than any other species. This also explains why many of the wild equids (horses and their relatives) are not tamed. Only the horse and the donkey could be tamed. The Asiatic wild ass (the onager) and the four species of zebra are irascible and given to much (and prolonged and sustained) biting.

The fifth characteristic is tendency to panic. It is important that domesticated animals be relatively slow in fleeing, not nervy, and have a tendency to herd up. Sheep and goats are excellent in this regard, but most deer and antelope are not. That is why gazelles have never been domesticated, as they will charge their enclosure walls at full speed when threatened.

The last characteristic is social structure. Successful domesticated large animals are those that live in herds, have a well-established dominance hierarchy and have overlapping ranges with other herds. Domestication for such animals takes place when humans can take over the dominance hierarchy. Young animals in such herds imprint on humans and learn to trust, respect and follow them. Most people do not realise that the reason horses are tamed is that they perceive the close position of the ears on the human as being that of a dominant animal. (Perhaps this is why Prince Charles has so much trouble with his horses.)

Most solitary, territorial large animal species do not lend themselves to herding. They are not tolerant, do not imprint on humans and are not submissive. That is why all large felines are not domesticated. Cats and ferrets are the only territorial species that have been domesticated, but then only for hunting and as pets, and not as food. Antelope can not be domesticated because males fight too much whenever their herds merge; they do not tolerate range sharing. Certain deer and sheep types (such as the bighorn) are not suitable because they do not have a well-established dominance hierarchy and the males spend all their time fighting.

So where does that leave us? Only a few of the eligible large animals are domesticable. The major successes are sheep, goats, cattle, pigs and horses. The minor (or poorer) successes are the Arabian camel, the Bactrian camel, llamas and alpacas, donkeys, reindeer, some water buffalo, yaks, Bali cattle and mithans. Most of the candidates and their successes evolved in Eurasia, some candidates but no successes in Africa, few candidates and fewer successes in South America, and nothing for Australia.

Domesticating Rare Breeds

It is germane for people involved in rare animal breeding to reflect on the reasons that livestock are livestock, because this might explain why some rare breeds are rare. They might be more nasty, less manageable, or less economic than other breeds within the same species.

On the other hand, all things being equal, it is also possible that the vagaries of human nature determine why some breeds are more popular than others. For example, there once were many thousands of Shropshire sheep in New Zealand, where there are now only several hundred. Personal fancy of energetic breeders helps drive the fashion or flavour of the month.

It should be possible to select one of the minor domesticated species (or even a fortuitous choice among the undomesticated species) and, by proper attention to modern genetic understanding of the basis of temperament development, to derive a line or strain that could lead to a more domesticated animal. After all, ancient agriculturalists, such as those early Egyptian civilisations, were able to domesticate the wild oryx antelope, as evidenced in hieroglyphics.

Perhaps it is merely a question of finding the right management technique for some of these species as has been done for the various domesticated deer species in New Zealand. It is not impossible that modern genetics may advance in understanding as to how to implant genes for placidity into some of the amenable undomesticated species (again most likely with certain of the African antelopes). In any case, any such reconstructed or redomesticated species would certainly qualify for the rare breed label.

Readers may choose to explore this subject further by reading Guns, Germs and Steel by Jared Diamond.

Lorne Kuehn is a retired Canadian scientist raising rare breeds on a farm on the Banks Peninsula, and originally wrote this for the newsletter of the New Zealand Rare Breeds Society.