Chick sexing
Encyclopedia
Sex
In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into a male or female variety . Sexual reproduction involves combining specialized cells to form offspring that inherit traits from both parents...
of chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
and other hatchlings, usually by a trained person called a chick sexer or chicken sexer. Chicken sexing is practiced mostly by large commercial hatcheries, who have two different feeding programmes, one for the female
Female
Female is the sex of an organism, or a part of an organism, which produces non-mobile ova .- Defining characteristics :The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male...
s (or hens) who are destined to lay egg
Egg (food)
Eggs are laid by females of many different species, including birds, reptiles, amphibians, and fish, and have probably been eaten by mankind for millennia. Bird and reptile eggs consist of a protective eggshell, albumen , and vitellus , contained within various thin membranes...
s for commercial sale, and the others for the male
Male
Male refers to the biological sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilization...
s (or cocks
Rooster
A rooster, also known as a cockerel, cock or chanticleer, is a male chicken with the female being called a hen. Immature male chickens of less than a year's age are called cockerels...
), most of which will be culled within days of hatching because they are irrelevant to egg production. A limited number may be kept and fattened for their meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...
. The chicken sexer puts the chicken hatchlings on the appropriate track early, enabling those chickens to receive optimal nourishment for their likely commercial role from an early age.
Different segments of the poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
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
Chick slaughtering
Chick culling is the culling of newly hatched male chickens for which breeders have no use. In an industrial egg-producing facility, about half of the newly hatched chicks will be male and would grow up to be roosters, which do not lay eggs and therefore provide no incentive for the breeder to...
almost immediately to reduce costs to the breeder.http://www.mercyforanimals.org/hatchery/
Methods of chick sexing
There are two chief methods of sexing chicks: featherFeather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
sexing and vent
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
sexing.
Vent sexing
Vent sexing, also known simply as venting, involves literally squeezing the fecesFeces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
out of the chick, which opens up the chick's anal vent (called a cloaca
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
) slightly, allowing the chicken sexer to see if the chick has a small "bump", which would indicate that the chick is a male. Some females have very small bumps, but rarely do they have the large bumps male chicks possess.
The sexual organs of birds are located within the body; the professional vent sexer has studied their external appearance, which can fall into as many as fifteen basic patterns, and learned to identify which ones are male and which female. Many professional vent sexers are Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese, where the method originated. A seminal paper about vent sexing was published in Japan in 1933 by Professors Masui and Hashimoto, which was soon translated into English under the title sexing baby chicks. After their discovery, interested poultry breeders hired those who had been trained in Masui and Hashimoto's technique, or sent representatives to Japan to learn it.
Alternative methods
Small poultryPoultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
farm
Farm
A farm is an area of land, or, for aquaculture, lake, river or sea, including various structures, devoted primarily to the practice of producing and managing food , fibres and, increasingly, fuel. It is the basic production facility in food production. Farms may be owned and operated by a single...
ers whose operations are not of sufficient size to warrant hiring a chicken sexer must wait until the hatchlings are four to six weeks old before learning the sexes of their chickens. At that time their secondary sex characteristic
Secondary sex characteristic
Secondary sex characteristics are features that distinguish the two sexes of a species, but that are not directly part of the reproductive system. They are believed to be the product of sexual selection for traits which give an individual an advantage over its rivals in courtship and aggressive...
s begin to appear, making it possible for anyone with a minimal amount of training to sex a chicken.
Trivia
- Chick sexing was featured in episode 7 of Dirty JobsDirty JobsDirty Jobs is a program on the Discovery Channel, produced by Pilgrim Films & Television, in which host Mike Rowe is shown performing difficult, strange, disgusting, or messy occupational duties alongside the typical employees. The show premiered with two pilot episodes in November 2003...
. - Chick sexing is Steve Smith's summer occupation on the November 16, 2008 episode of American Dad.
- Chick sexing was an important mode of employment for second-generation Japanese Americans (Nisei), who dominated the trade between the late 1930s and 1950s.
- The 'example of the chicken sexers' is famous in several debates in philosophy, especially in the internalism/externalism debateInternalism and externalismInternalism and externalism are two opposing ways of explaining various subjects in several areas of philosophy. These include human motivation, knowledge, justification, meaning and truth. The distinction arises in many areas of debate with similar but distinct meanings...
in epistemology.
External links
- Poultry: Sexing of day-old chicks as a sport
- How to tell the sex of Chicks - including general signs, breed specific tips and old wives tales.
- Abstract: The art of chicken sexing - a cognitive science discussion
- The art of chicken sexing - full article (PDF)