Part II : Poultry
Chickens, ducks, muscovies, geese, guinea fowl, quail, pigeons, and turkeys epitomize the concept of microlivestock. Throughout Africa, Asia, and Latin America they are (collectively) the most common of all farm stock. In many - perhaps most - tropical countries, practically every family, settled or nomadic, owns some kind of poultry. In the countryside, in villages, even in cities, one or another species is seen almost everywhere; in some places, several may be seen together. Although raised in all levels of husbandry, these birds occur most often in scattered household flocks that scavenge for their food and survive with little care or management.
Their size bestows microlivestock advantages, including low capital cost, low food requirements, and little or no labor requirements. They are also "family sized": easily killed and dressed, with little waste or spoilage.
These poultry species help meet the protein needs of the poorest people in the world. Some are raised even in areas where domestic cattle cannot survive because of afflictions such as trypanosomiasis and foot-and-mouth disease. Some are maintained under conditions of intensive confinement - provided a source of feed is available - and can be produced in areas with insufficient land for other meat-producing animals.
In addition, these birds grow quickly and mature rapidly. (For instance, a chicken can, under proper conditions, reach maturity in 26 months.) They adapt readily to being fenced or penned much, or all, of the time. And, compared with the major farm livestock, their life cycles are short and their production of offspring is high. Thus, farmers can synchronize production to match seasonal changes in the availability of feed.
Although poultry contribute substantially to human nutrition in the tropics, it is a small fraction of what it could be. The meat is widely consumed and is in constant demand. An excellent source of protein, it also provides minerals such as calcium, phosphorus, and iron, as well as the B-complex vitamins riboflavin, thiamine, and niacin. Nutritionally as complete as red meat, it is much lower in cholesterol and saturated fats. Poultry eggs are also important sources of nutrients. They are a renewable resource, easy to prepare, and are among the best sources of quality protein and vitamins (except vitamin C).
In spite of their numbers and potential, poultry are rarely accorded primary consideration in economic development activities. All in all, these small birds lack the appeal of large, four-legged livestock. Indeed, most countries have little knowledge of the contribution household birds actually make to the well-being and diets of their peoples. In some countries - even those where birds are widely kept - there is little or no poultry research or extension. And where such programs do exist they usually focus almost exclusively on the production of chickens under "industrial" conditions near cities (see sidebar, page 75).
Most developing countries now have these intensive chicken industries, in which birds are kept in complete confinement. However, these commercial operations provide food for people in the cash economy, not for subsistence farmers. Moreover, grain is sometimes diverted or imported to maintain these operations, perhaps causing food shortages, higher prices, or depleted foreign exchange. Thus, in this section we focus on other, neglected, aspects of poultry production.,
The neglect of poultry that scavenge around the rural farmhouses and in village yards is understandable. The birds are scattered across the countryside where extension programs are difficult to implement. Their presence is often so ingrained in traditional village life that they are taken for granted and ignored by the authorities.
Yet village poultry deserve greater attention. As converters of vegetation into animal protein, poultry can be outstanding. In fact, it is estimated that, in terms of feed conversion, eggs rank with cow's milk as the most economically produced animal protein, and that poultry meat ranks above that of other domestic animals.
Most Third World poultry flocks live a wary, half-wild existence, scrounging for insects, earthworms, snails, seeds, leaves, and leftovers from the human diet. From dung and refuse piles they salvage undigested grains, as well as insects and other invertebrates. Often the persons who care for them are women or children. Some keep the birds around the house, penning them at night for protection from predators and thieves.
This almost zero-cost production has, in spite of high losses, a remarkable rate of return. Any improvements that require the purchase of supplies cut severely into the profitability. The first step in improving the production of free-ranging poultry is vaccination against diseases (especially Newcastle disease, fowl pox, and Marek's disease) and a modest, supplemental feeding during times of seasonal scarcity.
THE INDUSTRIAL CHICKEN
Throughout modem livestock farming the trend is toward more intensive methods, and poultry specialists have set the pace. In many countries, since the 1920s, barnyard fowl have given way to egg and broiler factories. The old-fashioned chicken reared outside on corn stubbles for 5 or 6 months has been replaced by the broiler, mass-produced in controlled environment houses in 7 - 10 weeks.
As a result of this revolution in poultry raising, small farmers who once made a comfortable living from a few laying hens have been forced out of business. These economic changes have also forced poultry men to have larger and larger flocks to survive. The largest broiler-chicken companies even control their own breed development, feed production, house construction, slaughtering, and freezing, many even have wholesale outlets.
The rapid changes in poultry farming methods can be attributed to the application of advanced technology. The development of the incubator to replace the mother hen sitting her seasonal clutch of eggs was the first mayor step toward intensive poultry farming.
In addition, chickens were the first livestock to receive serious attention from geneticists. Before World War II, it was discovered that crossbreeding selected pure and inbred lines could result in dramatic increases in production. Hybrids tailor-made for egg or meat production quickly ousted the old pure breeds such as the Rhode Island Red White and Brown Leghorns, Light Sussex, and the various crosses among them. Chicken broilers made by crosses involving parents derived from Cornish and Plymouth Rock have supplanted all others.
This situation now prevails in most industrialized countries. The breeding of commercial stocks is in the hands of a few corporations for each commodity (white eggs, brown eggs, chicken broilers, turkeys) and each has national or even global distribution of its hybrid stocks.
A BREAKTHROUGH IN POULTRY HEALTH
Newcastle disease is endemic in developing countries and is a constant threat to poultry. Farmers dread this virus, first identified half a century ago in northern England that brings diarrhea, paralysis, and death to most poultry. It is severe, highly contagious, and can cause 100 percent mortality. When it strikes an area, farmers must kill all chickens - even healthy ones - to stop it from spreading.
Only Australia, New Zealand, Northern Ireland and some Pacific islands are unaffected. But, although the disease is not found in Australia, certain strains of the virus are present in Australian chickens. These strains are completely harmless, but Australian researchers have found that they induce antibodies that are effective against Newcastle disease.
In a joint project (funded by the Australian Centre for International Agricultural Research), scientists from Malaysia's University of Agriculture and Australia's University of Queensland* have put this to good use. They have produced a live culture of the harmless virus that farmers can spray onto feed pellets to vaccinate their birds.
Field tests of the new vaccine, carried out in Southeast Asia, have been extremely promising. Simply coating feeds with the virus seems to be enough to immunize some chickens, which then pass the immunity on to the others in the flock as well as to new hatchlings. In Malaysia, which has 49 million chickens and a population willing to pay a premium for tasty village poultry meat, one economist estimates that the vaccine might increase rural incomes by 25 percent.
Conventional vaccines must be stored under refrigerated conditions, which most villages lack. But the Malaysian workers made the Newcastle disease vaccine tolerant of heat. By selective breeding, they now have strains that resist 56ÝC for at least 2 hours. Thus, even in the tropics, the vaccine remains effective for several weeks without refrigeration. The researchers have also devised methods for coating the vaccine onto pelleted feeds. Because the virus can withstand heat, they use a machine designed for coating pharmaceutical tablets.
At this stage, the project is showing every promise of producing a cheap means of reducing Newcastle disease losses among chickens throughout much of the world. Already inquiries have come from other Asian countries and from Africa, and it is hoped that the vaccine may eventually benefit many countries.