Search results
Results from the WOW.Com Content Network
Mortalities, due mainly to cannibalism, can be up to 15% in egg-laying flocks housed in aviaries, [11] straw yards, [12] and free-range systems. [13] Because egg-laying strains of chickens can be kept in smaller group sizes in cage systems, cannibalism is reduced, [ 10 ] leading to a lowered trend in mortality as compared to non-cage systems.
Removing eggs each day, out of the sight of the hens, helps avoid broodiness not only in domestic poultry but also in some wild species in captivity. This continued egg laying means more eggs are laid than would occur under natural conditions. [9] [10] Poultry farming in battery cages also helps to avoid broodiness. [11] [12] [13]
Forced molting typically involves the removal of food and/or water from poultry for an extended period of time to reinvigorate egg-laying. Forced molting, sometimes known as induced molting, is the practice by some poultry industries of artificially provoking a flock to molt simultaneously, typically by withdrawing food for 7–14 days and sometimes also withdrawing water for an extended period.
Early experience can influence severe feather pecking in later life. [13] [20] [21] Commercial egg-laying hens have often already begun feather pecking when they are transferred to the egg laying farm from the rearing farm at approximately 16–20 weeks of age, and plumage quality can then rapidly deteriorate until peak lay at approximately 25 weeks of age.
The RSPCA "Welfare standards for laying hens and pullets" indicates that the stocking rate must not exceed 1,000 birds per hectare (10 m 2 per hen) of range available and a minimum area of overhead shade/shelter of 8 m 2 per 1,000 hens must be provided. Free-range farming of egg-laying hens is increasing its share of the market.
Hens lay between 5 and 17 eggs per clutch and the eggs take between 23 and 24 days to hatch. There are between five and 10 young per brood. [ 15 ] The young are raised by the female and fledge in one to four weeks, are completely independent by the tenth to twelfth week, and reach sexual maturity by age one (Ammann, 1957).
As is the case with chickens, various breeds have been developed, selected for egg-laying ability, fast growth, and a well-covered carcase. The most common commercial breed in the United Kingdom and the United States is the Pekin duck , which can lay 200 eggs a year and can reach a weight of 3.5 kg (7 lb 11 oz) in 44 days. [ 34 ]
However, once the industry successfully bred separate meat and egg-producing hybrids—starting in the 1920s and 1930s [10] —there was no reason to keep males of the egg-producing hybrid. As a consequence, the males of egg-laying chickens are killed as soon as possible after hatching and sexing to reduce financial losses incurred by the breeder.