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Microlivestock - Little-Known Small Animals with a Promising Economic Future
close this book Microlivestock - Little-Known Small Animals with a Promising Economic Future
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close this folder Part IV : Rodents
View the document 15 Agouti
View the document 16 Capybara
View the document 17 Coypu
View the document 18 Giant Rat
View the document 19 Grasscutter
View the document 20 Guinea Pig
View the document 21 Hutia
View the document 22 Mara
View the document 23 Paca
View the document 24 Vizcacha
View the document 25 Other Rodents

Part IV : Rodents


Rodents are the world's most widespread, adaptable, and prolific group of mammals. They reproduce well, grow fast, learn quickly, and adapt to a wide variety of local conditions. Many convert vegetation into meat efficiently, digesting some fiber, even though their stomach, like man's, is a simple one.

It seems probable, therefore, that some species would make suitable microlivestock - a notion supported by the previous domestication of the guinea pig, laboratory rat and mouse, gerbil, and hamster. Indeed, "ranching" rodents might be an effective way to increase food supplies in remote areas. It could also be a mechanism to ensure the survival of rare rodents whose natural habitats are being rapidly destroyed.



Rodents are already common foods in many countries and are valued items of commerce. It has been estimated that 42 of 383 cultures eat rodents.! But the fact that they are a major meat source is almost unrecognized. This is due in part to cultural misunderstanding. Rodents suitable for human food or other products do not live in filth, like common rats. They are clean and vegetarian. Like rabbits, they eat grass and grains.

In some regions of the world, cooked rodent meat is regarded as the epitome of dining. In many countries, local rodent species are the most eagerly sought meats. City markets in different parts of Latin America carry guinea pig, pace, capybara, and vizcacha. Markets in Asia may carry rice rats, cloud rats, and bandicoot rats. Those of rural Africa are filled with "bushmeats" - usually including grasscutters, giant rats, and several other rodent species. These are often preferred to the meat of domestic stock and fetch higher prices than beef. And the amounts of rodent bushmeat available are not minor. In one year, for example, hunters in Botswana have brought to market 3.3 million kg of meat of the rodent called springhare (see page 278).

Fondness for rodent meat is not restricted to the tropics. In the United States, squirrel was once a much sought treat. Fat, nut-fed grey squirrels went into Brunswick stew, which has been called the most famous dish to emerge from the campfires and cabins of Colonial America. Thomas Jefferson liked it. Today, squirrel is the country's number two game animal (after deer), and many are still eaten.

Ancient Romans kept fat dormice in captivity, serving them as a delicacy. "The fat dormice are fattened up in barrel-like pots like those in country houses," wrote Varro (116-27 BC). "One feeds these animals large amounts of acorns, chestnuts, or other nuts."2 This small rodent remains a prized food in Europe and still appears on tables in certain areas. The meat is regarded as a delicacy because it tastes of almonds and other nuts. Often it is roasted, broiled, and cooked with its cracklings.

Rodents have seldom been included in livestock programs or economic development plans. Yet human appetite has actually caused the extinction of a number of species. Caribbean Indians ate several endemic rodents (one of which was as big as a bear), and may have caused several species to become extinct just before the time of Columbus. Others may soon follow the same dismal route, including the beautiful cloud rat of the Philippines, the hare-like mare of Argentina, the vizcacha of southern South America, and the gentle hutias of the Caribbean.

The guinea pig is described in a later chapter, but as it is the epitome of a rodent microlivestock species, some historical background is given here. It was domesticated for food use at least 7,000 years ago, probably in what is now the central highlands of Peru and Bolivia. With only llama and deer available, the prehistoric Andean peoples had few readily available sources of meat. They adopted wild cavies, and found that these rangeland rodents (which are more closely related to porcupines than to rats or mice) were gentle, manageable, and easy to rear. By the time the Spaniards arrived in the 1500s, the "cuy" (pronounced "coo-ee," like the faint cry it makes) was a major food from Argentina to the Caribbean.

This impressed the conquistadores, who introduced cuys into Europe, where they also became a delicacy.3 Within a century, these easily transported animals began to appear on tables in many parts of the Spanish empire. Guinea pigs are now reared in campesino huts in the mountains of central Mexico, in the Philippines, and in several African nations, along with other areas of the world.

Elsewhere, guinea pigs came to be used only as house pets and laboratory animals. Although during World War II Mussolini's government urged Italians to keep them to supplement their meager meat rations, their use as food was largely ignored in most parts of the world.



The idea of domesticating rodents may seem radical, but domestication projects are already under way with capybara in Venezuela (see page 206), pace in Panama (see next page and page 262), giant rat in Nigeria (see page 224), and the grasscutter in Ghana (see page 232). Rodent husbandry is not complicated and the animals' environmental requirements seem relatively simple and easy to satisfy. Moreover, rodents are not usually fastidious feeders, and being essentially vegetarian will readily accept a wide variety of commonly available foodstuffs.



As with most animals with which man is in close contact, rodents can transmit human diseases.4 With care, however, managed rodents need not be any more dangerous to care for or to eat than pigs or horses - both of which are worldwide food resources.



To domesticate the pace (see page 262) would seem to be impossible. These large rodents of Central and South America are nocturnal and fiercely territorial; they have low fecundity and take 10 months to reach weaning, and they have tender skin that is easily damaged Most researchers have written them off as candidates for domestication. But at least two have undertaken to beat the odds. We present the findings of one of them here to show that, using modem techniques, even species that normally fight each other to the death on sight are potential farm animals.


Through years of studying paces in Panama, Smithsonian biologist Nicholas Smythe has found that with care and planning the aggressive behavior can be so radically altered that the animals become calm. Indeed, some become almost loving. Newborns, Smythe found, undergo "imprinting" and when he places them with docile adults or with humans, the fierce territoriality never develops. He nurses newborns on "surrogate" mothers that have been imprinted on people. The youngsters then welcome human company and, if fumed out of the cage, return there voluntarily. "It's difficult to imagine a more manageable animal," Smythe said. "Technically speaking they are behaviorally indistinguishable from traditional domestic animals."

As of this writing, Smythe has three generations totalling about 50 individuals, and has several "families" of gentle paces living together in harmony. He has observed that they lose their nocturnal habit and, although they live mainly on fruits in the wild, they readily eat leafy vegetables and other foods in captivity. His captive specimens have recently begun to breed. The offspring remain docile, but they have so far averaged only a little more than two young per female per year.

"If we can just double the reproduction rate, then raising paces can compete economically with raising cattle," Smythe explained. "The potential for a bigger brood is all in the animal's anatomy, and if successful, paces in the wet tropics could produce as much protein as cattle."*

Pacas need the shade and protection of the forest. Thus, pace raising might provide an alternative to cutting down rainforests for cattle raising. Instead of toppling trees and planting pastures, people could farm paces in the forest, and perhaps make as much or more money at the same time. In tropical America, the ready acceptance of pace meat is a near guarantee that all they produce will be snapped up at premium prices. In the past, many territorial and aggressive species have been dismissed as being impossible to domesticate or manage. But Smythe has demonstrated that with imprinting and other methods of behavior modification, these need be dismissed no longer.

Indeed, the pace may already be becoming a new domesticated species. In the first stage of his experiments, Smythe had to train his captive-born paces to be social and nonaggressive. Subsequent generations, however, need no training adopt the new behavior patterns of the parents, and do not revert to aggressive asocial behavior. By the third generation, they have become as accepting of, and indifferent to, people as cattle or sheep.