|Auburn University Digital Library|
|Microlivestock - Little-Known Small Animals with a Promising Economic Future|
source ref: b17mie.htm
|Part III : Rabbits|
The domestic rabbit (Oryctolagus cuniculus)1 is suited to small-scale production and backyard farming. It is easily maintained, requires scant space, makes minimal demands on the family budget, and thrives on plant materials that are usually disdained by humans. It utilizes forage efficiently. even coarse vegetation that is high in fiber, and under ideal conditions it can grow so rapidly that its rate is only slightly lower than that of broiler chickens.2
The rabbit's capacity for reproduction is legendary. In theory, a single male and four females can produce as many as 3,000 offspring a year, representing some 1,450 kg of meat - as much as an average sized cow.3 The meat is pink, delicately flavored, and is usually considered a premium product that provides variety in the diet. It has more protein and less fat and calories per gram than beef, pork, lamb, or chicken.
Some breeds are raised for their wool. The long-haired Angora, for instance, yields a luxury fiber that makes a soft, lustrous fabric. It sells at high prices and makes these animals very valuable.
Rabbit pelts also bring cash. They are used in fur coats and other luxury garments. In addition, rabbit feet and tails are used in good luck charms and many curios.
AREA OF POTENTIAL USE
APPEARANCE AND SIZE
Rabbits are well known for their long ears, fluffy tails, and long hind legs. Many commercial breeds are white, although colored types are sometimes chosen because of special qualities in their meat or pelts.
There are many breeds and much genetic diversity within and between breeds. (Almost 160 varieties are recognized by the American Rabbit Breeders Association.) However, in both North America and Europe, the New Zealand White has traditionally displaced most other breeds for commercial meat production. This medium-weight breed bears large litters, is a good milk producer, and has good mothering ability. It reproduces best under intensive farming and, among purebreds, yields the most meat. A full-grown New Zealand White weighs 4-5 kg, giving about 2 kg of meat at 8-10 weeks of age. Large breeds include the Flemish Giant or the Checkered Giant, which weigh more than 6 kg at maturity.
Hybrids are rapidly replacing purebreds in Europe for commercial production. Specific crosses of breeds have been shown experimentally to be more productive overall compared with purebred New Zealand Whites.
Different meat breeds are preferred in various countries. For example, in Ghana the most popular are Flemish Giants, New Zealand Whites, Yellow Silvers, and Checkered Giants; in Tanzania and Nigeria, New Zealand Whites and Dutch are preferred; in China, Chinchillas and Japanese Large Whites are the most widely consumed. Some smaller breeds - for instance, the Polish - are also valuable for husbandry.
Some Third World strains have already evolved. They show high tolerance to local conditions (for example, the Baladi - the main strain of the Sudan and the Near East - and the Criollo of Mexico). The Baladi has a small body and relatively low production, but it is hardy and tolerates harsh conditions.
Specialized breeds have been developed for wool, fur, and laboratory research. The Angora wool breed has already been mentioned. The Rex breed produces a high-quality pelt used in furs.
The wild ancestor of the domestic rabbit was originally restricted to Spain and Portugal. Today, its descendants are found worldwide.
HABITAT AND ENVIRONMENT
Domestic rabbits are best suited to temperate climates, but they do well in tropical and subtropical conditions if hutches are constructed and sited to take advantage of shade and cooling breezes. Ventilation is important (but care must be taken to avoid direct exposure to cold drafts). Prolonged exposure to temperatures higher than 30ÝC reduces both fertility and growth. Apparently, all breeds tolerate heat equally well. However, heat is shed through the ears, and the longer the ear, the more heat a rabbit will tolerate. Lop-eared varieties withstand heat poorly.
Rabbits eat fibrous vegetation. In addition to normal feces, they produce special droppings called cecotropes. Softer and smaller than the regular fecal pellets, they are excreted in clusters and are swallowed as soon as they are eliminated. Cecotropes are rich in bacterial protein, and this double digestion (coprophagy) enables the animals to utilize the fermentation products formed in the cecum. This process is rather like that of ruminants, and rabbits are sometimes called pseudoruminants.4
Breeding begins at 4-6 months of age and may continue up to age 4, occasionally to age 6. Gestation takes 28-32 days. Females can conceive within 24 hours after giving birth and can produce a second litter merely 4 weeks later. With good feed and early rebreeding, 9 or more litters a year are possible. (Such a rate is only achievable under exceptional management, however.) Litter size depends on breed and body weight. Small breeds average 4 young per litter; large breeds 810. Births occur at any time of the year, but production slackens when the weather is exceptionally cold or hot, when feed is scarce, or when days are short. Extremes of heat or cold can also affect the survival of the young.
Rabbits raised under subsistence conditions are likely to produce 4 or 5 litters a year, with an average of 5-8 young per litter' depending on management and feed quality.5 Annual production of about 20 weaned offspring per female per year under tropical and subtropical conditions is common. The young remain in the nest until they are 2-3 weeks old. Their eyes open at approximately 10 days of age. About 4 months are required to produce a 2-kg market rabbit under subsistence conditions.
Rabbits that receive human handling are very gentle and can be trained to live inside people's houses and even use a "litter box."
Rabbits are multipurpose animals yielding the following products:
- Meat. Delicious hot or cold, fancy or plain, it can be breaded and fried, broiled, baked, or barbecued.
- Wool. The fineness of rabbit hair is an asset in the production of wool, which is the plucked or shaved hair of the long-haired Angora breed. It is usually mixed with fine Merino sheep wool to give more substance and to improve its wearing quality. An average Angora rabbit produces about 850 g of wool each year. (Some specimens produce as much as 1,000 g.)
- Fur. The fur is dense.
- Leather or vellum. Rabbit hide has the tension and strength required for tiny drive-belts in tape recorders and other delicate machines.
- Fertilizer. Rabbit manure often contains high proportions of nitrogen, phosphorus, and potash, and it comes in convenient drypellet form.
- Tourist charms. In many societies, rabbits are connected with good luck. Feet and tails are used for car decorations, key chains, charms, and mementos that appeal to tourists.
Rabbits are also used in biochemical and physiological research.
Rabbits can be housed in hutches ranging from sophisticated commercial cages to simple packing crates with a few ventilation holes and rough troughs for food and water. In all cases, watertight roofing is essential. A floor space of only 0.25 mÝ is sufficient for one rabbit, but about 1 mÝ is recommended for a female and her young.
Starting small-scale rabbit production is generally inexpensive. An almost infinite variety of backyard feeding and drinking equipment can be made from various scrap items, such as old bottles. The main criteria are that cleaning should be easy and spillage minimized.
In practice, diets can be based largely on herbage: grass, leaves, legumes, crop residues, and kitchen scraps. However, the diet must be wholesome, and caged rabbits fed on forage usually need some grain or agricultural by-products (rice bran, for instance) as a dietary supplement. Supplementation is particularly important for newborns and lactating females, whose diet must contain about 16 percent protein and at least 18 percent fiber. When "noncommercial" feeds are used, salt must be added to prevent salt deficiency.
Because of higher protein content, legumes (for instance, alfalfa, cowpea, vetch, or pea) are better than grass. Alfalfa is particularly valuable, and in the Sudan and Mozambique it is already grown extensively for feeding rabbits. On diets consisting of alfalfa and rye grass, weaned New Zealand Whites have demonstrated growth rates of 38-39 g per day in animals weighing up to 2 kg.
Rabbits, as mentioned, can utilize almost any type of edible vegetation. Also, despite their diminutive size, they can collectively produce as much meat per unit of forage as large livestock, or even more (see page 183).6
There is much genetic diversity. Differences in growth rate, fertility, maternal ability, milk production, disease resistance, heat resistance, and other features have been noted. This is useful, since a wide genetic base enhances the likelihood of success of selection programs.
Rabbits are easy to handle and can be raised under primitive conditions. They require little financial investment and their husbandry is easily accomplished in the home by women and children.
The animal's rapid reproduction is a big advantage.
Tropical conditions produce special problems. There, rabbits must be protected from heat and rain. Stress brought on by high temperatures, high humidity, and wet conditions can lead to respiratory disorders and even sudden death.
Most diseases are caused by poor management. Dirty or wet cages lead to diarrhea, sores, mites, and ringworm, all of which can cause serious losses. Enteritis (diarrhea) often kills 20 percent or more of all rabbits before they attain market age and weight. A major disease problem in most countries is coccidiosis, which is particularly harmful to young rabbits. Again, damp and unsanitary conditions increase the susceptibility; better management can control it.
In some countries - notably Australia and New Zealand - escaping rabbits have become a serious menace and have destroyed crops and grazing lands. Because of this threat, it is illegal to import rabbits into some countries.
At present, many people are unaccustomed to eating rabbit. Indeed, where commercial ventures have been established in areas with an otherwise plentiful meat supply, there have been financial failures. However, where rabbit meat is familiar, there is usually great demand for it. Also, in poorer areas where animal protein is in short supply, the tasty pink meat is widely appreciated.
HOW RABBITS WERE DOMESTICATED
For 30 or 40 million years the wild species Oryctolagus Cuniculus lived only in the area that today is Spain. Caves there contain Stone Age drawings of it. Phoenician traders landing on the Iberian Peninsula in about 1100 B.C. found huge numbers of these wild rabbits. The little animals were unknown to them and they mistook them for the hyraxes they had seen in Africa. (Although small and rabbitlike, the hyrax is actually related to elephants.) Since the Semitic name for hyrax was shaphan ("one who hides"), the Phoenicians named the peninsula l-shepan-im, from which the Latin name Hispania developed. Thus, "Spain" actually means "island of hyraxes," even though these African animals have never occurred there.
Given the rabbit's reproductive powers and adaptability it is surprising that it hadn't spread beyond Spain, but dense forests covered most of Europe after the last Ice Age. The rabbit, which is suited to open country, only spread rapidly after man had cleared most of the trees. Even then, the natural spread was slowed by the Pyrenees mountains blocking the way into the rest of Europe.
Ancient Romans became acquainted with rabbits after they invaded Spain, and they eagerly added wild rabbit meat to their banquets. The meat was so popular that around 1 A.D. Roman voyagers released a pair of rabbits onto the Balearic Islands. In time, these produced so many offspring that the islanders had to appeal to the Roman emperor for help. They even asked to be moved to another country if the emperor could not get rid of the plague of rabbits!
Eventually, Romans in Italy, France, and other parts of the European mainland began raising rabbits for meat. They kept them in special cages called leporaria. Their rabbits were probably not truly domesticated; instead they were netted in the wild and caged for fattening before being prepared for the table. The Romans had little incentive to domesticate an animal that could be so easily captured.
Tne rabbit was the last farm animal to be domesticated. It seems likely that this did not begin until the Christian era when monks in French monasteries began taming rabbits. In those days, rabbit embryos and newborn young were considered delicacies, called "laurices." In 600 A.D. the Pope declared that laurices were "not meatp," and permitted them to be eaten during fasts and in monasteries of strict discipline where meat was forbidden. Within a few years, the animal was domesticated,
RESEARCH AND CONSERVATION NEEDS
Government-sponsored rabbit-research stations and programs are found in France, Germany, Italy, Spain, the United States, and the United Kingdom.
Rabbit husbandry is well known, but much basic research is needed; for example, specific nutrient requirements, breed comparisons, disease control, reproductive management, and efficient housing and equipment. There is a particular need to reduce the labor required for feeding, breeding, caging, and cleaning.
With the increasing number of rabbit programs in Africa, Asia, and Latin America, there is a need to share information and ideas among the various countries. The exchange of experiences with rabbit breeding, health and nutrition, and the practical experiences and field studies could be of great value.
Further research in rabbit nutrition is necessary to identify nutrient requirements more precisely. Moreover, links between nutrition and disease should be clarified.
Further research into the cause and prevention of enteritis is needed. (At present, this condition is prevented by maintaining a fiber level in the diet of at least 18 percent and keeping the energy level relatively low.)
Legume shrubs could be an answer to the feed problems in the dry season. Deep-rooted shrubby legumes, such as gliricidia or leucaena, remain green well into the dry season and have high protein contents. Rabbits find the leaves of leucaena palatable (see companion report Leucaena: Promising Forage and Tree Crop for the Tropics. National Academy Press. Washington, D.C. 1984), and they are fairly resistant to mimosine (a sometimes toxic amino acid found in leucaena foliage). More research on this promising approach is needed.
As noted earlier (page 181), a killer virus has recently appeared. Studies into its epidemiology and control are most important.
Outsiders who hope to improve conditions in underdeveloped areas, sometimes . . . introduce new food avoidances to the communities they came to help [if outsiders] show repugnance toward consuming goats, . . . rats, . . . crows, insects, intestines and blood, then the people they are educating may likewise give up those . . . foods and lose valuable proteins.
Calvin W. Schwabe
You can count on the fingers of one hand the domestic animals that produce virtually all of mankind's meat and milk - a selection made more than 10,000 years ago by our Neolithic ancestors. Yet the earth teems with thousands of species of animals; why limit ourselves to cattle, pigs, goats, and sheep? Given the world's shortages of energy and water and arable land, why not try to domesticate wild animals? The effort would save many species from extinction, provide the world with more food, and introduce gentle farming to fragile environments.