Chicken
From Poultry Hub
Chickens or "chooks" provide us with a number of products, including meat from specially bred broilers (meat chickens) and eggs from layers (egg laying chickens). During the past many families owned their own flock of hens to supply them with meat and eggs. Today, in Australia, most chicken meat production is carried out as an intensive livestock enterprise by commercial producers. The Australian chicken meat and egg industries are separate industries that use different chicken breeds, housing and production systems. The two industries are owned and managed by separate groups of people.
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Meat chickens (broilers)
The chicken meat industry produces meat and uses a different type or breed of chicken than that used for egg production. Some meat type breeds can produce 1 kg of liveweight from less that 2 kg of feed. Strains of chickens bred for meat production area called meat chickens. The word broiler is an American term for meat chickens which is not commonly used in Australia because it can be confused with boiler, which in Australia means an old or spent hen that has finished its productive life as a layer. A dressed fowl is one that has been killed, plucked, and had its feet, neck and internal organs removed. It might seem more correct to say it has been undressed, but the term derives from the bird being dressed up to go to market.
Egg laying chickens
The Chicken layer industry produces eggs for humans to eat, called table eggs. There are special varieties of chicken, called laying strains, some of which can lay over 300 eggs per hen per year. Strains of chickens bred to lay eggs are called layers. Depending on the strain of bird used, egg colour can range from tinted (cream) to brown.
Ancestry and behaviour of the chicken
The ancestry of the domesticated chicken can be traced back to the Asian jungle fowl otherwise known as the red jungle fowl. Jungle fowl are predominantly ground dwelling birds living in areas with dense overhead vegetation. Social groups typically consist of one male with up to four females and their chicks, although larger groups of up to 20 birds can form in more open environments. Other males are either solitary or form unisexual groups of two or three birds. Family groups have a well-defined home range and a regular roosting location.
Flocks spend the majority of the day on the ground and generally only roost at night or in response to perceived danger. Foraging for food comprises up to 75% of activity during the day. Maintaining plumage condition through preening and dust-bathing is also a consistent daily activity. The breeding season varies but is generally in the spring and summer in temperate zones, where breeding is stimulated by increasing day length and halted by decreasing day length in autumn. Breeding is all year round in tropical areas.
Jungle fowl are ground layers, hens select a nest site that is a well concealed hollow that may or may not be lined with grass or leaves. They lay a “clutch” (a set of eggs produced or incubated at one time) of five to eight eggs. They then become broody (physiologically ready to incubate eggs after having completed egg laying) and sit on the eggs to incubate them. Hens cease to be broody and drive the chicks away when they are six to eight weeks old.
Observations of the behavior of jungle fowl are useful in understanding the underlying behavioral drives of domestic chickens, however it has not been satisfactorily quantified how much domestication may have modified these drives. By comparison, domestic chickens are less active, have fewer social interactions, are less aggressive to would-be predators, and are less likely to go looking for foreign food sources than their wild ancestors. As a result of spread around the globe and domestication a large number of breeds of domestic chicken (Gallus gallus domesticus) have been developed.
See also
- Poultry
- Breeding chickens
- Chicken layer industry
- Chicken meat industry
- Breeder farm sequence
- Meat chicken farm sequence
- Layer farm sequence
- Introduction to anatomy and physiology
- Evolution of the bird
- The egg
- Chicken recipes
