Good egg-laying breeds of chicken are Leghorns, Minorcas, and Anconas; varieties most suitable for eating are Dorkings, Australorps, Brahmas, and Cornish; those useful for both purposes are Orpingtons, Rhode Island Reds, Wyandottes, Plymouth Rocks, and Jersey White Giants. Most farm poultry are hybrids, selectively crossbred for certain characteristics, including feathers and down.

Factory farming

Since World War II, the development of battery-produced eggs and the intensive breeding of broiler fowls and turkeys has roused a public outcry against ‘factory’ methods of farming. The birds are often kept constantly in small cages, have their beaks and claws removed to prevent them from pecking their neighbours, and are given feed containing growth hormones and antibacterial drugs, which eventually make their way up the food chain to humans. Factory farming has led to a growing interest in deep-litter and free-range systems, although these account for only a small percentage of total production.

Factory farming has doubled egg yields and increased the availability of poultry meat. In 1988, over 450 million chickens and 30 million turkeys were sold in the UK for meat. However, in 1988-89 the UK egg industry suffered a major blow when it was discovered that Salmonella bacteria, which can cause food poisoning, were present in large quantities of eggs. Chickens were slaughtered and farmers lost large amounts of money. Eggs were declared safe only if boiled or heated to a high enough temperature to kill the bacteria.

In the UK, most ducks are raised for their meat, the breeds most commonly reared being the Pekin and the Aylesbury; geese are kept in fairly small numbers, efforts to rear them intensively having proved largely unsuccessful. Apart from the small-bodied Chinese breed, which, in a year, may lay up to 100 eggs, geese are not prolific egg producers.

In France and elsewhere in mainland Europe, geese and duck are force-fed to produce the delicacy pâté de fois gras; of the two, goose fois gras is considered the greater delicacy.

In 2004 scientists announced the mapping of the chicken genome (of the red jungle fowl Gallus gallus). The chicken genome was found to contain 1 billion base pairs of DNA and between 20,000 and 23,000 genes.

images

egg-packing

poultry