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Delayed Feathering In Chickens
Delayed-feathering in chickens is a genetically determined delay in the first weeks of feather growing, which occurs normally among the chicks of many chicken breeds and no longer manifests itself once the chicken completes adult plumage. The difference between fast normal feather development and delayed-feathering can be recognized in one-day-old chicks but is always more evident in 10- to 12-day-old chicks. Female chicks have a slightly faster feathering than males. Barely seen in breeds with fast normal-feathering, this characteristic is better observed in breeds with delayed feathering, like Barred Plymouth Rock.Hutt, F.B. Genética Avícola. Salvat Editores,S.A. 1ra.ed. España (1958) Natal down color is not related to feathering speed, but in chickens of full-black adult plumage, chicks normally have shorter natal down than those from breeds of any other plumage color pattern this shortening being more obvious in the head and back. Feathering growth in the first wee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
407x208px-emplume Comparativo
4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures. In mathematics Four is the smallest composite number, its proper divisors being and . Four is the sum and product of two with itself: 2 + 2 = 4 = 2 x 2, the only number b such that a + a = b = a x a, which also makes four the smallest squared prime number p^. In Knuth's up-arrow notation, , and so forth, for any number of up arrows. By consequence, four is the only square one more than a prime number, specifically three. The sum of the first four prime numbers two + three + five + seven is the only sum of four consecutive prime numbers that yields an odd prime number, seventeen, which is the fourth super-prime. Four lies between the first proper pair of twin primes, three and five, which are the first two Fermat primes, like seventeen, which is the third. On the other hand, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remiges
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail are called rectrices (), singular rectrix (). The primary function of the flight feathers is to aid in the generation of both thrust and lift, thereby enabling flight. The flight feathers of some birds have evolved to perform additional functions, generally associated with territorial displays, courtship rituals or feeding methods. In some species, these feathers have developed into long showy plumes used in visual courtship displays, while in others they create a sound during display flights. Tiny serrations on the leading edge of their remiges help owls to fly silently (and therefore hunt more successfully), while the extra-stiff rectrices of woodpeckers help them to brace against tree trunks as they hammer on them. Even flightless birds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feathers
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier example of a complex evolutionary novelty. They are among the characteristics that distinguish the extant birds from other living groups. Although feathers cover most of the bird's body, they arise only from certain well-defined tracts on the skin. They aid in flight, thermal insulation, and waterproofing. In addition, coloration helps in communication and protection. Plumology (or plumage science) is the name for the science that is associated with the study of feathers. Feathers have a number of utilitarian, cultural, and religious uses. Feathers are both soft and excellent at trapping heat; thus, they are sometimes used in high-class bedding, especially pillows, blankets, and mattresses. They are also used as filling for winter clothin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Anatomy
Bird anatomy, or the physiological structure of birds' bodies, shows many unique adaptations, mostly aiding flight. Birds have a light skeletal system and light but powerful musculature which, along with circulatory and respiratory systems capable of very high metabolic rates and oxygen supply, permit the bird to fly. The development of a beak has led to evolution of a specially adapted digestive system. Skeletal system Birds have many bones that are hollow ( pneumatized) with criss-crossing struts or trusses for structural strength. The number of hollow bones varies among species, though large gliding and soaring birds tend to have the most. Respiratory air sacs often form air pockets within the semi-hollow bones of the bird's skeleton. The bones of diving birds are often less hollow than those of non-diving species. Penguins, loons, and puffins are without pneumatized bones entirely. Flightless birds, such as ostriches and emus, have pneumatized femurs and, in the case of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
627x150px-emplume Tardío
6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number. In mathematics Six is the smallest positive integer which is neither a square number nor a prime number; it is the second smallest composite number, behind 4; its proper divisors are , and . Since 6 equals the sum of its proper divisors, it is a perfect number; 6 is the smallest of the perfect numbers. It is also the smallest Granville number, or \mathcal-perfect number. As a perfect number: *6 is related to the Mersenne prime 3, since . (The next perfect number is 28.) *6 is the only even perfect number that is not the sum of successive odd cubes. *6 is the root of the 6-aliquot tree, and is itself the aliquot sum of only one other number; the square number, . Six is the only number that is both the sum and the product of three consecutive positive numbers. Unrelated to 6's being a perfect number, a Golomb ruler of length 6 is a "perfect ruler". Six is a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chick Culling
Chick culling or unwanted chick killing is the process of separating and killing unwanted (male and unhealthy female) chicks for which the intensive animal farming industry has no use. It occurs in all industrialised egg production, whether free range, organic, or battery cage. However, some certified pasture-raised egg farms are taking steps to eliminate the practice entirely. Worldwide, around 7 billion male chicks are culled each year in the egg industry. Because male chickens do not lay eggs and only those in breeding programmes are required to fertilise eggs, they are considered redundant to the egg-laying industry and are usually killed shortly after being sexed, which occurs just days after they are conceived or after they hatch. Some methods of culling that do not involve anaesthetics include: cervical dislocation, asphyxiation by carbon dioxide, and maceration using a high-speed grinder. Maceration is the primary method in the United States. Maceration is often a pref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broiler
A broiler is any chicken (''Gallus gallus domesticus'') that is bred and raised specifically for meat production. Most commercial broilers reach slaughter weight between four and six weeks of age, although slower growing breeds reach slaughter weight at approximately 14 weeks of age. Typical broilers have white feathers and yellowish skin. Broiler or sometimes broiler-fryer is also used sometimes to refer specifically to younger chickens under , as compared with the larger roasters. Due to extensive breeding selection for rapid early growth and the husbandry used to sustain this, broilers are susceptible to several welfare concerns, particularly skeletal malformation and dysfunction, skin and eye lesions and congestive heart conditions. Management of ventilation, housing, stocking density and in-house procedures must be evaluated regularly to support good welfare of the flock. The breeding stock (broiler-breeders) do grow to maturity but also have their own welfare concerns re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chick Sexing
Chick sexing is the method of distinguishing the sex of chickens and other hatchlings, usually by a trained person called a chick sexer or chicken sexer. Chicken sexing is practiced mostly by large commercial hatcheries to separate female chicks or "pullets" (destined to lay eggs for commercial sale) from the males or "cockerels" (most of which are killed within days of hatching because they are irrelevant to egg production). The females and a limited number of males kept for meat production are then put on different feeding programs appropriate for their commercial roles. Different segments of the poultry industry sex chickens for various reasons. In farms that produce eggs, males are unwanted; for meat production, separate male and female lines for breeding are maintained to produce the hybrid birds that are sold for the table, and chicks of the wrong sex in either line are unwanted. Chicks of an unwanted sex are killed almost immediately to reduce costs to the breeder. Metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterogametic Sex
Heterogametic sex (digametic sex) refers to the individuals of a species in which the sex chromosomes are not the same. For example, in humans, males with an X and a Y sex chromosome would be referred to as the heterogametic sex, and females having two X sex chromosomes would be referred to as the homogametic sex. This arrangement is known as the XY sex-determination system. However, in birds and some reptiles, males have two Z sex chromosomes and so are the homogametic sex, while females, with one Z and one W chromosome, are the heterogametic sex. Platypus males are heterogametic while females are homogametic. Among the insects, Lepidopterans (butterflies and moths) have heterogametic females, but in ''Drosophila'', males are the heterogametic sex. This arrangement is known as the ZW sex-determination system. Heterogamesis can lead to reduced or absent meiotic recombination between the sex chromosomes, and in some species, this extends to the autosomes, a phenomenon called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancona (chicken)
The Ancona is a breed of chicken which originated in the Marches, region of Italy, but which was bred to its present type mainly in the United Kingdom in the nineteenth century. It is named after the city of Ancona, capital of the Marche. It is popular in Britain and the United States, but uncommon in Italy; an initiative to re-establish it in its native area and preserve its biodiversity was launched in 2000. There are also Ancona bantams. History The Ancona originated in central Italy, where it was the most widely distributed breed of chicken. The first Ancona chickens were imported into England in 1851, and selectively bred there for regularity and consistency of the white markings in the plumage. In 1880 a breeder named Cobb showed a group. Some birds were exported from Britain to the United States in 1888. Rose-combed Ancona chickens were first shown in Birmingham in 1910. In the United States, the single-comb Ancona was recognised by the American Poultry Association ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minorca (chicken)
The Minorca, ca, Gallina de Menorca, italic=no, es, Menorquina, italic=no, is a breed of domestic chicken originating in the Mediterranean island of Menorca, in the Balearic Islands to the south-east of Spain. It is a well-known exhibition bird in many countries of the world, but in the island of Menorca is an endangered breed and considered to be at risk of extinction. History The international type of Minorca was created by the British from indigenous Menorcan birds. This process began during the British occupation of the island from 1708 to 1783, but It is not clear if it took place there or in Britain. It is likely that it began in Menorca and continued in Britain, where imports of chickens from Menorca in the 1780s are documented. By about 100 years later, the breed (which was considered a variety of the "Spanish") was common and long-established in Devon and Cornwall, in the south-west of England, where it was highly regarded as an egg-laying breed. It had been exhibited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leghorn (chicken)
The Leghorn (, ; it, Livorno, italic=no or Livornese) is a breed of chicken originating in Tuscany, in central Italy. Birds were first exported to North America in 1828 from the Tuscan port city of Livorno, on the western coast of Italy. They were initially called "Italians", but by 1865 the breed was known as "Leghorn", the traditional anglicisation of "Livorno". The breed was introduced to Britain from the United States in 1870. White Leghorns are commonly used as layer chickens in many countries of the world. Other Leghorn varieties are less common. History The origins of the Leghorn are not clear; it appears to derive from light breeds originating in rural Tuscany. The name comes from Leghorn, the traditional anglicisation of Livorno, the Tuscan port from which the first birds were exported to North America. The date of the first exports is variously reported as 1828, "about 1830" and 1852. They were initially known as "Italians"; they were first referred to as "Leghor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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