Dictionary of Poultry words and terms:

Glossary of Poultry words and terms:

This is I hope a comprehensive alphabetical list of the terms and slang of poultry and chicken keeping.  If I have missed anything or you have any local or slang poultry terms you would like to see included please let me know.


ABA - American Bantam Association.

Abdomen - area between the keel and the pubic or hip bones.

Abdominal cavity – the internal cavity of the poultry that contains the majority of the internal organs.

Abdominal capacity - the evaluation of a hen giving an indication of the state of egg production. Determined by using the hand to estimate the distance between the ends of the pubic bones and between the tips of the pubic bones and the end of the keel. Also an assessment by a judge at a poultry show.

Acclimatization - long-term physiological adaptation resulting in increased tolerance to repeated or continuous exposure to multiple climatic stressors, usually under natural conditions.

Acute - a condition that is relatively short and severe, but not chronic.

Adaptation - physiological, behavioural, genetic or other changes that favour the welfare, survival and reproduction of an animal in a particular environment.

Additive - a substance added to the diet that is not a natural nutritive ingredient.  Could include medications, pigments, flavourings, enzymes, prebiotics or probiotics.

Additive gene - a gene which has greater expression in the homozygous state than in the heterozygous state or which influences degree rather than kind of expression.

Adjuvant - additive to vaccine to enhance its effectiveness.

Air cell - the air space between the two shell membranes, usually at the large end of the egg unless it has becomes detached during shipping or rough handling.

Aetiology - causes of a disease.

Albumen - the white of the egg, which is actually clear and only goes white when cooked. The albumen is built up in layers in the oviduct and is mostly protein and water. It is the albumen that becomes the chick during incubation.

Alektorophobia - the fear of chickens, or sometimes it’s not the bird but the flapping of wings. (Also Ornithophobia – fear of birds).

Allantois - a sac connected to the embryo's abdomen and involved in embryo respiration, nutrition and excretion.

Allele - one of a pair of genes that can occur at the same locus on a chromosome.

Allergy - hypersensitivity of a bird to a particular substance.

All-in All-out - a flock of birds enters and exits a facility as a single group.  New birds are not introduced and flocks are not mixed.  This strategy minimizes the risk of new birds introducing disease agents into a flock.

Allometry - the study and measurement of the size or growth of a body part relative to the whole body.

Altricial - birds that usually have little down at hatching and that are not mobile, thus unable to leave the hatching area. 

American Standard of Perfection - book published by the American Poultry Association that closely outlines the standard of recognized breeds in the United States.

Amino acid - primary organic chemical units that combine to form various proteins.  Those considered essential in the diet are: methionine, threonine, lysine, arginine, glycine, histidine, leucine, isoleucine, tryptophan, phenylalanine, and valine.

Amnion or Amniotic sac - membrane that closely surrounds the embryo filled with amniotic fluid which protects the developing embryo from shock and provides a medium for the develop embryo to exercise their muscles.

Anatomy - the structure of the bird in question. The different systems of the bird, their location and how they interact.

Androgen - hormone produced primarily in the testes and is involved in semen production and the presence of male secondary sex characteristics.

Anaemia - an abnormally low number of red blood cells in the circulatory system.

Anthelmintic – A group of anti-parasitic drugs given to treat a birds with parasites. The names sometimes end in –zole or –mectin although there are others. They kill or stun the parasites so they can be passed from the body.

Antibiotic - a chemical produced by a microorganism or fungi and used to destroy or inhibit the growth of bacteria and other microorganisms.

Antibody - a natural substance in the blood that recognizes and destroys foreign invaders and that causes an immune response to vaccination or infection.

Antigen - a foreign protein in the blood that differs from natural body proteins and, as a result, stimulates the natural production of antibodies.

AOB – Any Other Breed.

AOSB - Any Other Standard Breed.

APA – the American Poultry Association is in charge of setting the standard for pure bred poultry in the United States, and they are in charge of maintaining the publication of the American Standard of Perfection which outlines breed specification for the standard of exhibition poultry. Particular breeds accepted or admitted to the "Standard of Perfections" are often referred to by year thus informing customers as to how long this breed has been recognized as a standard breed of poultry in the United States. The American Poultry Association is an extremely strong advocate for expanding the knowledge of poultry among breeders and the general public, as well as encouraging the raising and showing of poultry.

Arboreal - adapted to tree-living or living mostly in trees.

Area opaca - the early stages of a developing blastoderm it is the white outer ring surrounding the inner translucent area in which the embryo first forms.

Area pellucida - in the early stages of a developing blastoderm it is the central translucent area in which the embryo first forms, and which is surrounded by a white ring.

Area vasculosa - the area around the early embryo in which blood is first formed. Blood islands form first and then develop into a vascular system that is connected to the embryo.

Artery - vessels that transport blood away from the heart.  Compare Vein.

Arthritis - inflammation of a skeletal joint.

Artificial insemination - a technique in which semen is collected from the male and deposited, with or without dilution, in the vagina of the female.  Currently used in almost all commercial turkey breeding operations as the birds are often too large for natural mating. Also used in rare and exotic bird species, and in research and pedigree mating.

Ascites - accumulation of fluid in the abdominal cavity, can be caused by organ failure or tumours. As a rule this is a condition of older fowl.

As hatched - description of a group of chicks that have not been sorted or sexed in any way.

Ataxia - lack of coordinated muscular movements as in epidemic tremors or “crazy chick disease”.

Auto sexing - determining the gender of the chick by a characteristic such as feather colour or feather growth.  Obtained by using sex-linked genetic characteristics. Cream crested Legbar are Auto sexing fowl

Autosome -any chromosome that is not a sex chromosome.

Aves - a class of animals that contains all birds

Avian - pertaining to birds

Avian Influenza - a respiratory disease caused by a virus similar to those causing human influenza.  The mild form causes decreased egg production and low mortality, whereas the acute form causes high mortality and affects multiple body systems. Currently in 2016 causing considerable concern to poultry concerns worldwide.

Aviary - a large enclosure for holding birds in confinement, although chickens keepers tend to call them runs. The term aviary is mostly confined to caged birds like budgies.

Aviculture - the science of birds and their habits

Axial feather - the short wing feather located between the primary and secondary flight feathers


Backcrossing - a breeding procedure in which a crossbred is mated to one of its parents or parental types. Used in line breeding to accentuate certain characteristics of one bird.

Backyard flock - a small, non-commercial poultry flock kept for home use, showing, or other purposes.

Bacteria - single-celled micro-organisms containing no chlorophyll that often cause diseases.

Banding - putting on a leg ring, tag or band with identification on it to the wing or feathers of a bird. Racing pigeons of have their identity and a phone number etched or painted onto the open wing feathers. Leg rings are the most common with chickens and are either coloured or numbered.

Bantam - a chicken breed that is one third to one half the size of a standard breed. Except for those breeds that are bantam only and have no large fowl counterpart like Japanese bantams.

Banti (Banty) or Banties - a non-technical term sometimes used in place of bantam.

Barny – slang term for a Barnevelder.

Barb - the branches or projections from either side of the rachis or shaft of a feather, which in turn have barbules and barbicels as substructures.

Barbicels - tiny hooks that hold a feather's web together. Looks and works a bit like Velcro.

Barring - Alternate markings of two distinct colours on a feather, for example a barred rock.

Barnyard chicken - a chicken of mixed breeds common in small home flocks. Sometimes mongrels or chance mating but often collections of rare breeds.

Basal metabolic rate (BMR) - the minimal heat production of a normal bird that is awake, resting, and resting metabolic rate (RMR) is measured when birds are resting but not fasting and may be at a temperature below thermoneutral zone.

Bay - light golden brown colour.

Bacterin - A killed bacterial vaccine, consisting of a suspension of whole bacteria.

Basket - A 15-dozen shipping container made of plastic or wire used by shell egg producers and packers for packaging of cartoned eggs. Cardboard box 15-dozen shipping containers are also referred to as baskets.

Basted - The industry practice of injecting a specific volume of liquid into raw poultry and poultry parts to improve tenderness, juiciness, or flavour and to improve cooking time. The basting solution may be broth, butter, or vegetable oil or a mixture with herbs or other flavourings.

Battery cages - cages, usually made of wire that are used to keep hens or growing birds.  They may be stacked in moveable units or in stationary long rows of one or more levels. Cause of much controversy.

Bid - A verifiable price that a buyer is willing to pay to secure product.

Beak – or the bill or rostrum the hard protruding mouth part of a bird consisting of an upper and a lower part (Mandibles) and is used for eating, fighting, grooming and courtship. They are bony projections.

Beard - the feathers bunched together under the beak of some breeds of chickens like the owlbeard or the coarse hairs protruding from the breast of turkeys.

Bedding – material, sometimes called litter, scattered on the floor of a poultry house to absorb moisture and manure.

Bevy - a flock of quail or swan.

Biddy - a non-technical term for a laying hen that is over one year of age. Or older.

Bill - the beak of waterfowl.

Billing out - the act of chickens using their beaks to scoop feed out of a feeder and onto the floor to the absolute frustration of the chicken keeper.

Biosecurity – a programme designed to prevent disease from infecting a property or spreading between premises.

Blackhead - the disease Enterohepatitis Histomoniasis, more common in turkeys and some game birds. Symptoms are sulphur coloured droppings, lethargy, and liver lesions

Blade - the lower, smooth part of a single comb.

Bleaching - the disappearance of the colour from the vent, face and shanks of yellow-skinned chickens. It happens in a predictable pattern and can be used to tell how long the bird has been in lay.

Blood spot - blood in an egg, sometimes also called a meat spot. Around 2 to 4% of eggs have some sort of blemish in them. It depends on the variety of chicken and other factors. In the US, eggs with blood spots larger than an eighth of an inch in diameter are graded “inedible” under federal regulations, and shouldn’t end up in your fridge. There is some evidence that brown eggs have a higher incidence.

Bloom - the moist protective coating on a freshly laid eggs that partially seals the pores of the egg shell to prevent penetration by bacteria, sometimes called the cuticle.

Blowout – Slang or colloquial term for a prolapse or when there is vent damage, typically caused by laying a very large egg. Tends to be more common in hybrids as they lay larger eggs more often.

Blue - slate grey feather colour. Mutation of the black gene.

Body temperature - most domestic birds thermoregulate to a body temperature of 41 to 42°C (105.8 to 107.6°F).  Some birds, such as ostrich, have lower temperature and others will become temporarily torpid.  The upper lethal body temperature in the chicken is 115 to 116.6°F (46.1 to 47.0°C).

Booted - having feathers on the shanks, or legs, and toes.

Brassy - a yellowish tint sometimes seen in white-feathered birds. Often shows after a moult.

Breast blister - Swelling over the keel bone with bruising and discolouration. Could be enlarged, discoloured area on the breast or keel bone often seen in heavy birds. General issue with more than one cause.

Breed - a defined chicken type having a standard and distinctive body shape and the same general features, like Wyandotte for example. Or the term used when group male and female birds for mating.

Breeder(s) - mature chickens from which fertile eggs are collected or person who manages chickens.

Breed true - the characteristic of purebred chicks whereby they resemble both parents.

Broiler - a meat-type chicken that is usually less than 12 weeks of age and has been bred specifically for meat production.

Brood - to care for a batch of chicks, either with a broody mother hen or artificially with heat pats, artificial hens or heat lamps.

Brooder - an area used to provide warmth to young chicks.

Broody - a hen that is sitting on eggs with the intent of hatching them, or caring for her young family.

Botulism - Paralysis of the neck, caused from toxins ingested from boggy areas with rotting vegetation or animals

Buff - orange-yellow colour in feathers that is not shiny or brassy.

Bumblefoot - A large swelling on the bottom of the foot caused by an infection - typically caused by a small cut or injury.

Buttercup Comb - this comb is set on the top and middle of the head and looks like a cup-shaped crown with a circle of small and regularly spaced points. For example the Sicilian Buttercup Chicken.


Cackle - the sounds characteristically made by a hen and following the laying of an egg.

Cage layer fatigue - a weakness or paralysis in laying hens kept in cages caused by calcium and phosphorus imbalances in a period of high egg production, with phosphorus being most important.  Other factors may also be involved.

Candle - to examine the contents of an intact egg through the shell with the use of a powerful directional light.

Candler - light used to examine the contents of an egg without cracking it open.

Candling – the act of using a Candler to check the contents of an egg, either before incubation to test the suitability of the egg or during incubation to monitor the progress of the embryo’s development.

Cannibalism - when poultry eat the flesh of fellow flock mates, either from a bird that has died or a live one that has an open wound.

Cape - narrow feathers between a chicken's neck and back. Their shape is often used for determining the sex of the bird.

Capon - a castrated male chicken. Illegal in most parts of the world as it is considered barbaric. Requires surgery since the reproductive organs are internal.

Carcass - edible parts of a slaughtered animal, including edible viscera like chicken liver.

Carrier - an apparently healthy bird that can transmit a disease to others. Also refers to a container or boxes used to transport Poultry.

Carriage - posture of the bird.

Caruncle – Bright red growths on the throat region of turkeys and the face of Muscovy ducks.

Cere - the enlarged, unfeathered and waxy, fleshy area around or above the nostrils of birds such as pigeons, budgerigars and waterfowl.

Cecum - a blind (only has one opening) pouch at the junction of the small and large intestines that hosts a community of microorganisms that can ferment (digest) fibre (plural = ceca). Chickens have 2.

Chalazae - two white cords of tightly spun albumen (egg white) found on either side of the yolk and important in keeping the yolk properly positioned within the egg (plural = chalazae).

Cheep - sounds of young chicks.

Chick - young or baby chicken.

Chicken tractor - a portable pen for chickens on pasture, usually enclosed to keep the birds in safe confinement.

Chick tooth - a tiny, hard projection on the beak of a newly hatched chick that was used by the chick to break the shell to hatch. Also called an egg tooth, it drops of within 48 hours.

Chook - an Australian term for chicken that has been used in the US for chickens in a small flock.

Chorion - a membrane the surrounds the yolk sac and amnion.

Class - a group of chicken breeds that were originally developed in a particular region of the world or egg grades are often called classes. See also grades.

Clean legged - having no feathers on the shanks or toes.

Clears - Incubated eggs that appear clear when candled, indicating that they do not contain a live embryo

Cloaca - the portion of the avian anatomy where the intestinal, reproductive and urinary tracts end. There are three areas of the cloaca, the coprodeum or anterior area in which the digestive system empties, the urodeum or middle area in which the ureters of the urinary system enter dorsally and the vas deferens of the male or the oviduct of the female enter laterally, and the proctodaeum which is the external opening (vent) of the cloaca.

Clocker – what we call a broody hen in the North of England.

Clubbed down - a condition where the down feathers do not erupt from their feather sheath resulting in a coil-like or stubby appearance. A riboflavin deficiency in the egg is considered to be one cause of the condition in the embryo/chick.

Cluck - sound a hen makes.

Cock – or Rooster. An adult male chicken. Or an adult male pigeon.

Cockerel - immature male chicken.

Coccidia - protozoan intestinal parasite. Can be fatal.

Coccidiosis - a parasitic infection (coccidia) in the intestinal tract of poultry.

Coccidiostat - a drug used to keep poultry from getting coccidiosis.

Coefficient of inbreeding - the mathematical expression of the degree of inbreeding present in an individual or group of birds.

Coliform - any bacteria resembling Escherichia coli.

Columbian - a plumage pattern in chickens consisting of white except black in the neck, primary wing, and tail feathers.

Columella - the single bone in the ear of a bird.

Comb - The fleshy and usually red outcrop of skin atop the chickens head. The comb, along with the beak and the wattles, help the chicken regulate body temperature helping them cool themselves. There are nine recognized varieties of combs among chickens:

Condition - typically refers to a chicken's state of health and cleanliness

Conformation - refers to the body structure of poultry and how well they conform to the breed standard or the standards of perfection.

Conjunctiva - mucus membrane associated with the eyes.

Conjunctivitis - infection of the conjunctiva.

Contagious - disease that is easily passed from one bird to another.

Contract grower - a farmer that grows chickens, under contract, for a broiler company. For example contractors who grow black rocks on from their genuine supplier.

Coop - the house or cage in which poultry are kept. A coop is the structure that houses the chickens, and it usually contains one or multiple roosts and nesting boxes for egg laying. Coops can be a wide variety of styles and sizes depending on the flock size and personal preference. We sell both Pre Made Chicken Coops as well as Chicken Coop Plans to help you build your own.

CRD - Chronic Respiratory Disease, a common disease of chickens that is characterized by sneezing and difficulty breathing. Commonly controlled with antibiotics usually administered in feed or drinking water.

Cornish game hen - A young chicken (usually 4 to 6 weeks of age) not more than 2 pounds in dressed weight.

Cornish - a breed of the English Class of chickens having large skeleton and heavy breast muscles.  They are used as the base male stock for commercial meat type chickens.

Coryza - an upper respiratory infection especially affecting the nasal passages, sinuses and eyes. 

Coturnix quail or Japanese quail - a small Asian ground-dwelling bird (Coturnix japonica) that has been bred and used commercially for meat and egg production.  In nature they are migratory.  The breast meat is dark.

Coverts - feathers that cover the base of primary wing, secondary wing, and main tail feathers.

Cramming - a system of individually force-feeding birds to produce fattened table birds or livers for pate de foie gras. 

Crazy chick disease – encephalomalacia is seen in commercial flocks if diets are very low in vitamin E.

Creeper fowl - an inherited condition (heterozygote) in which the bird has shortened leg bones.  The homozygous dominant condition is lethal like in Japanese bantams.

Covey - a flock of quail.

Coverts - feathers that cover the primary and secondary wing feathers

Crest - ball or line of feathers on the heads of some breeds of chickens, ducks and geese

Crop - enlarged part of the digestive tract of birds that serves as a temporary storage space of food. This can be seen when full.

Crop bound - a condition in which the crop is filled with impacted material that is not moved on through the digestive system.

Crop, pendulous - a crop extended with material and hanging in front of the bird’s breast.  It is more common in turkeys and older fowl.

Crop, sour - the material in the crop is not evacuated and becomes fermented with a sour or foul odour.

Crossed beak - an abnormal condition in which the upper beak (maxilla) is curled to one side and misaligned with the lower beak (mandible).

Crossbred - the offspring of parents from two different breeds.

Crosses - progeny resulting from the mating of two varieties, breeds, or genetic stocks.

Crow head - a narrow, shallow head and beak.

Crude protein – a measure or calculation of the protein content of a feed or feed ingredient based on analysis for nitrogen.  The amount of nitrogen is multiplied by 6.25 as on average, proteins contain about 16% nitrogen.

Crude fibre - that portion of a feed or feed ingredient that remains insoluble (primarily cellulose) after treatment with hot sulfuric acid and then hot potassium hydroxide, minus the ash.

Crumbles - feed with particle size intermediate between mash and pellets.  Usually pelleted feed that has been partially broken. 

Cryptomere - a genetic character that is not expressed because of masking by another gene.

Crusty Butt - a slang term for pasting, especially in mismanaged chicks.

Cuckoo - a course and irregular barring pattern in feathers.

Cull - to remove a bird from the flock because of productivity, age, health or personality issues. Often done to remove surplus cockerels. Not necessarily killing of birds. Chickens might be culled from a breeding program but be fine for producing eggs.

Cuticle - the moist protective coating on a freshly laid eggs that partially seals the pores of the egg shell to prevent penetration by bacteria, sometimes called the bloom.

Culture – to incubate a sample from a diseased bird to look for the presence of bacteria by producing a large quantity in controlled conditions.

Cushion - mass of feathers that gives a round effect seen in birds like Orpingtons’ and cochins.

Cushion Comb - small comb that lies flat on top of the chicken's skull with no discernible pattern. Chantecler Chickens

Cygnet – baby or young swan till it grows its adult feathers.


Dander - Small particles of dead skin or feather particles. The poultry equivalent of dandruff.

Dam - Mother.

Dam family - Sibling chickens that all have the same dam as well as sire.

Debeaked - remove a portion of a bird's top beak to prevent cannibalism or self-pecking.

Defect - any characteristic that negatively effects the points a chicken scores in a show, or a reason that certain chickens should not be selected for breeding from.

Depopulate - to destroy an entire flock.

Dewlap - the flap of skin below the beak of turkeys and some geese

Diapause - the period of the embryo’s life from the time the egg is laid until placed in an incubator or the hen begins incubation.  A time of little or no development.

Disinfect - kill bacteria through chemical or other, mechanical means, or heat. Diatomatious earth works mechanically.

Dished bill – upward curving bill in waterfowl

Disqualification - a defect or deformity serious enough to bar a bird from a poultry show.

Diet - feed prepared from a mixture of ingredients.

Display - behavioural movements of birds during courtship prior to mating, for example, the male turkey fans the tail feathers and wings, engorges the caruncles and struts prior to mating.

Dominance, genetic - a character that suppresses its allele in the heterozygote individual.  In incomplete dominance the allele is only partially suppressed.

Dorsal - the back, or toward the back or upper surface of the body.

Double-yolk - an egg having two yolks, usually the result of two ova being ovulated at the same time.  It may also result from one ovum not being picked up by the infundibulum on the day of ovulation. The record is seven yolks in one egg.

Down - a layer of feathers found under the tough exterior feathers. Particularly renowned in eider ducks.

Drake - an adult male duck.

Dressed - cleaned in preparation for eating. Feathers and guts removed and sometimes trussed.

Droppings - another term for chicken manure.

Dry-Bulb Temperature - temperature measured with a standard thermometer

Dub - to surgically remove a bird's comb and wattles close to the head, usually after fighting or frostbite.

Duck foot - a disqualification of chickens where the hind toe is carried too far forward and touches the third toe or is carried too far back and touches the ground.

Duckling - a young (baby) duck

Duodenal loop - the upper part of the small intestine (also referred to as the duodenum)

Dry-bulb thermometer – A thermometer freely exposed to the air but shielded from radiation and moisture. DBT is the temperature that is usually thought of as air temperature, and it is the true thermodynamic temperature. It used to determine the temperature in a room or incubator.

Dust bath - the habit of chickens to splash around in soft soil to clean their feathers and discourage external parasites.

Dusting - When a chicken rolls around in the dirt, flinging it on themselves and in between their feathers as a method of cleaning the feathers and discouraging parasites.


Ear lobes - the flesh patch of bare skin located below the ears of birds

Ectoparasite - an external parasite

Easter egger - An Easter Egger is any chicken that possesses the "blue egg" gene, but doesn't fully meet any breed standard defined in the American Poultry Association's (APA) standards, or in the case of Easter Egger bantams, the American Bantam Association's (ABA) standards. The name derives from the resemblance of their colourful eggs to Easter eggs.

Egg - the reproductive cell of the female bird.  The major parts are yolk with germinal cell, albumen, membranes, and shell.  All of the nutritional elements necessary for embryonic development are present in the egg.  Only the blastoderm is living tissue.

Egg Bound - When a hen cannot pass her egg normally through the oviduct. Often fatal.

Egg dipping - a procedure in which warm eggs are submersed in a cool liquid containing antibiotic, hormone, or other active substance that is drawn into the egg as it cools and contracts.

Egg Drop Syndrome - an adenovirus-caused disease in laying birds characterized by severe decreases in egg production accompanied by eggshell abnormalities.

Egg flat or tray - moulded plastic or paper, commonly containing 30 cone-shaped moulded cups, each holding one egg placed small end down.  These are placed in cases or boxes for moving and storage. 

Egg shell - the hard calcareous coating of the egg that functions to provide physical protection and a barrier to microorganisms, permits gaseous exchange for the embryo, and is a source of nutrients and calcium for the embryo.  The shell is approximately 95% mineral of which 97 to 98% is calcium carbonate with small amounts of magnesium carbonate and tricalcium phosphate.

Egg residue - Hatch residue.

Egg tooth - a tiny, hard projection on the beak of a newly hatched chick that was used by the chick to break the shell to hatch.  Also called a chick tooth.

Egg Sizes - Shell eggs are divided by size (class) according to weight. Minimum net weight per dozen: Jumbo - 30 ounces, Extra Large - 27 ounces, Large - 24 ounces, Medium - 21 ounces, Small - 18 ounces. UK has 4 egg sizes - Very Large 73g + over, Large 63--73g, Medium 53--63g, Small 53g + under.

Electrolytes - a mineral solution used to treat dehydration

Embryo - the developing chick in an egg

Embryology - the study of the formation and development of embryos

Emu - a large flightless bird of Australian origin similar to the ostrich, but smaller, that is used some for meat production.

Encephalomalacia - neural degeneration due to a vitamin E deficiency.  Also called Crazy Chick disease.  Results in lack of muscle coordination.

Encephalomyelitis - Epidemic Tremors.  Affects the brain and nervous system and may result in ataxia, prostration and death.  Caused by a virus infection.

Endemic - commonly present in a particular population or geographical location.

Endocrine glands - glands that produce internal secretion(s) that are carried by the blood to other tissues whose actions and functions they affect.  Examples are thyroids, pituitary, adrenals, pancreas, gonads, and intestine.

Endotoxins - Toxins produced by bacteria.

Encephalitis - inflammation of the brain

Endoparasite - an internal parasite

Enteric - affecting the intestines

Enteritis - inflammation of the intestines

Evaporation - changing a liquid into vapour

Exhibition Breeds - A chicken or duck breed that is bred and raised primarily for showing and ornamental purposes rather than a utility such as egg laying or meat production. Often, most Fancy Breeds fit into the category of Exhibition Breeds.

Exudate - fluid associated with an inflammation or swelling

Exudative diathesis - accumulation of fluid (exudate) under the skin or around the heart

Eye stripe - a dark marking in some birds, especially chicks, that surrounds the eyes and may go toward the back of the head.  Sometimes considered to be a wild type of marking. Occasionally useful for sexing chicks.


Faking - the dishonest practice of concealing a defect or disqualification from a potential buyer or a show judge

Faecal - pertaining to the faces

Faces - droppings/manure

Fancier - a breeder of exhibition type birds used for showing.

Fart egg - A fart egg, also known as a wind egg, is a small egg that is typically laid by a young hen (pullet). These eggs usually do not contain a yolk and were often thought to be laid by roosters in olden times.

Feather - outer covering of the bird’s body, modified scales attached to the skin in follicles.  Feathers are a unique anatomical feature of the bird.  Under natural environmental conditions the bird will replace (moult) most feathers one or more times a year.  Laying hens are managed in later production stages by induced moulting and rejuvenation of the reproductive system

Feather-legged - a description of those breeds of chickens with feathers growing down their shanks, also feather footed or booted.

Feral – wild or untamed.

Fertile – Description of an egg from a chicken that has been covered by a cockerel, an egg that is fertilized and thus capable of having a chick develop under the correct environmental conditions.

Fertility - percentage of eggs that are fertile

Finish - the amount of fat under the skin of a meat bird.

Flock - a group of birds living together.

Flight feathers - the large primary and secondary feathers of the wings

Fluff - downy feathers

Foie gras - French for 'fatty liver' and is a food product made from the liver of a duck or goose that has been specifically fattened for this purpose.

Follicular Cyst - When a feather follicle is facing the wrong way, so the feather is aimed and grows inside of the bird's body instead of outside.

Fomite - inanimate objects such as shipping crates, feed sacks, clothing, shoes, and tires that may harbour disease-causing organisms and thus able to transmit the disease.

Foot candle - a measurement of light intensity.

Forage - to scratch the ground in search of food. Also refers to the crops in a pasture and a type of chicken raising practise, i.e. pasture raised chicken.

Forced-air incubator - an incubator that has a fan to circulate the air to keep a more accurate and even air temperature in all areas of the incubator.

Forced moult - the partial or whole moulting of feathers intentionally induced by changes in environment, diet or other means.  The physiological process also includes the rejuvenation of the reproductive system to partially restore egg production rate and egg quality thus extending the productive life of the hen. Normally a yearly cycle if left to happen naturally.

Fowl - domesticated birds raised for food or other similar purpose.

Free-range - a term that has various legal definitions depending on where you are in the world. Refers to birds with outdoor access during daylight hours.

Frizzle - a feather that curls rather than laying flat. Looks like a bed head bird. The feathers often curl upwards.

Fryer - a young meat-type chicken


Gander - a male goose

Gamebirds - several varieties of bird species including Pheasants, Quail, Partridge and Grouse that have been hunted for food and sport. This term can also be used for various types of wild waterfowl and wild turkeys. These bird can be raised in captivity, but they are not considered domestic poultry and can be released onto their own after a certain number of weeks.

Gapeworms - very small roundworms that infest the trachea.  Male and female worms are permanently attached.  Intermediate hosts include earthworms and snails but are not necessary for infection.

Gene - units occurring at specific points on chromosomes by which inherited characters are transmitted to progeny and which function as determinants of physiological processes.  Some may act as on-off switches for other genes.

General purpose breed - a breed of chicken that has good egg production and which is large enough with sufficient fleshing to also provide meat, especially the surplus cockerels.  They are not efficient enough for commercial stock but are often used in home flocks. Also called utility fowl.

Genetics - the area of biological science that deals with heredity and variation in organisms and, when applied, is used to change characteristics of the organism.

Genetic drift - performance characteristics such as egg production or growth rate tend to change from an established level in the absence of intentional selection.

Genital eminence - a small bump on the inner ventral wall of the cloaca that differs slightly between male and female newly hatched chicks and which is used by sexers to differentiate sex of the chicks.

Genotype - the characteristics of an individual determined by genetic components.

Genus - a classification of animals or plants having common distinguishing characteristics; a subdivision of a family and may consist of one or more species.

Germinal disc - the site of fertilization, if it occurs, in an egg

Germs - disease causing organisms

Giblets - the parts of a chicken carcass that consist of the heart, gizzard and liver.

Gizzard - a portion of the avian digestive tract with thick muscular walls that crushes and grinds food

Glair – older English term for egg white

Gobbler - an adult male turkey (also a 'tom')

Goose - a type of waterfowl; the female of the species is also referred to as a goose (the male is a gander)

Gosling - a young (baby) goose

Grade - to sort according to quality. With eggs both the contents and the shell are graded. They are then classified according to size

Grit - small pebbles eaten by birds and used by the gizzard to grind up feed

Guinea Fowl - breed of poultry that originated in Africa that is raised for a variety of utilities. They are most commonly raised for their meat as well as pest control, specifically ticks. Their watchfulness and strong territorial instincts make them excellent natural guardians. They do well when they are allowed to roam wide distances in a flock, and they are only partially domesticated.

Guinea hen - an adult female guinea fowl

Guinea pullet - a female guinea fowl under one year of age

Guinea cock - an adult male guinea fowl

Guinea cockerel - a young male guinea fowl under one year of age


Hackles - feathers over the back of a chicken which are pointed in males and rounded in females.

Hatch - the process by which the chick comes out of the egg. Collective term for emergence from eggs. 

Hatchability - the percentage of fertile eggs that hatch when incubated

Hatchery - a place where eggs are incubated and chicks hatched

Head spot - a light coloured spot in the down on the head of chicks having sex-linked barred feathers.  It can be used for identifying the sex of chicks from Barred Plymouth Rocks and some other breeds and crosses.

Heart rate - the number of beats per minute, or pulse rate.  Heart rate is 200 to 400 beats per minute in the chicken, varying inversely with body size.

Heavy Hen - A breeder hen, usually over 7 pounds live weight, no longer commercially productive for laying broiler type hatching eggs. Younger heavy hens are marketed as baking or stewing hens, older heavy hens are marketed as

Helminthes - a category of parasitic worms

Helminthiasis - parasitic worm infestation.

Hen - adult female poultry including chicken, turkey, duck, pigeon, pheasant, etc.

Hen feathered - the characteristic of some breeds of chickens where the male has rounded feathers (rather than pointed) like those of a female. Slang term – Henny. Makes birds even more difficult to sex.

Hock - the 'knee' joint of a bird.

Homeostasis - a tendency to maintain a normal and stable state in the body.

Horizontal transmission - disease passed bird to bird of the same generation usually though faeces, fluids, feather dander, contact or airborne methods of transmission. See also vertical transmission.

Host - an animal that has a parasite or an infectious agent living on or in it

Hover - canopy type brooding system

Humidity - the amount of water vapour in the environment (usually measured with a wet bulb thermometer)

Hybrid - offspring of parents from different breeds (also referred to as crossbred); the artificial crossing of two different species


Immunity - resistance to disease (active immunity develops when an individual has had the disease or been vaccinated; passive immunity is passed from mother to chick through the egg).

Impaction - the blockage of a part of the digestive tract, typically the crop or cloaca.

Imprint - the behaviour and memory of a young bird is fixated on another bird, animal or object in such a manner that it elicits certain responses in later life.

Inbred - offspring of closely related parents.

Inbreeding - The practice of mating closely related birds, such as father to daughter or brother to sister. As inbreeding increases, the ability of the stock to reproduce usually declines.

Incubate - to apply the required conditions (heat and humidity) to eggs to allow embryos to develop and chicks to hatch out.

Incubation period - the time it takes for an egg to hatch once incubation starts; also refers to the time from exposure to a disease causing agent to the time when the first symptoms of the disease appear.

Incubator - a piece of equipment especially designed to incubate eggs.

Inedible - Eggs that are not allowed for human consumption. They are segregated and sold primarily to pet food companies.

Infectious - capable of invading living tissue and multiplying so as to cause a disease.

Infertile - an egg that is not fertilized and therefore will not hatch.

Infertility - the inability to reproduce (can be with either the male or female and can be a temporary or permanent condition).

Infundibulum - The beginning of the oviduct that picks up the ovulated yolk when it is released from the ovary (also called the funnel).

Ingest - to eat.

Insemination - placement of semen from the male into the oviduct of the female.  Artificial insemination is essential in commercial turkeys and can be used in some breeds of chickens and other species to improve fertility.  It is often used in research studies of reproduction and in some breeding programs.  Artificial insemination is labour intensive.

Intensity of lay - how well a hen is laying right now?

Intraocular - in the eye.

Intranasal - in the nose.

Intravenous - injection into a vein.

Iris - coloured circle that surrounds the black centre in the chicken's eye.

Isthmus - the part of the female reproductive tract where the inner and outer shell membranes are added.


Jake - a young male turkey.

Jejunum - a portion of the small intestine.

Jenny - a young female turkey.


Keel - the breast bone of birds.

Keet - a young (baby) guinea fowl.

Keratin - key structural material of feathers (as well as wool, hooves, and human skin, hair and nails).

Knob - protrusion from the skull.


Lacing - border of contrast colour around the entire web of a feather.

Lamella - the tooth-like serrations of the inner edges of the bill of ducks and geese.

Large intestine - a short portion of the intestine extending from the ileocecal junction to the cloaca, functioning primarily in water absorption.  The large intestine of some birds, like ostriches, is very large and appears to function in the digestion of fibre.

Large Fowl - Regular sized chickens, as opposed to Bantam Chickens, that usually range between 4 and 13 pounds depending on breed and gender. Chickens are usually categorized into Light and Heavy Breeds. Most Light Breeds are going to be White Egg Layers.

Lash egg - The correct term for the condition causing a lash egg is Salpingitis which is an inflammation of the oviduct where the egg begins its travels. The lash egg is not a true egg but may contain bits of egg material and a lot of pus and other material. They can be disgusting to deal with and odd to see. Your hen may well need treatment as the condition can easily be fatal.

Layer or Laying Hen - Refers to a female chicken that has begun laying eggs

Layer cycle - the period of the layer’s life from onset of lay until cessation of lay and a natural moult.  The cycle may be intensively managed for economic purposes in commercial flocks.

Leg - the limb on which the bird walks, namely the thigh, drumstick and shank.

Leg Band - bands of plastic or metal placed around the bird’s leg as a means of identification.  It may be a simple colour code or it may have a number or bar-code.

Leghorn - a breed of chicken of the Mediterranean Class that has been used extensively as a base breed for egg production purposes.  It produces a white-shelled egg.

Legume - any of thousands of plant species that have seed pods that split along both sides when ripe. 

Lesion - abnormal tissue caused by injury, disease or parasite.

Lethal gene - a genetic condition that results in abnormal development and death of the embryo.  In some cases the embryo may survive beyond hatching but then die, either directly due to the condition or indirectly due to blindness or other conditions that prevent normal activities. 

Leucosis - a viral disease of birds causing enlargement of the liver, spleen and kidneys as the bird grows and matures.  Partially prevented by vaccination.  The complex of diseases include Marek’s disease, lymphoid leucosis, osteoporosis, erythroblastosis, and reticuloendotheliosis.

Leukocyte - a type of white blood cell that is involved in the immune system.  Macrophages engulf and destroy infectious agents and cellular debris.

Libido - the urge for sexual activity.

Lice - External parasites.

Light breed - breeds of chickens, such as Leghorns, that generally have characteristics such as small body size, higher metabolic rate, non-broodiness, and high rate of egg production.

Light schedule or pattern - the hours of light and dark to which birds are subjected each 24-hour period, including natural and artificial light, intensity, light colour, and changes in light.

Light stimulation - the use of light to stimulate the hypothalamus, pituitary and pineal glands resulting in stimulation of the reproductive system and other effects.

Limber neck - a condition caused by botulism poisoning.

Line breeding - a system of inbreeding emphasizing use of descendants from a specific ancestor or group of ancestors.

Leaker - an egg that leaks because the shell is cracked and the shell membrane is broken.

Litter - material scattered on the floor of a poultry house to absorb moisture and manure (bedding)

Lopped comb - a comb that falls to one side


Macrophage - A cell which can ingest and destroy foreign cells such as bacteria.

Magnum - the portion of the avian oviduct in which the thick white (albumen) is added

Malformation - embryos with abnormalities ranging from minor to severe.  There are numerous causes for malformations.

Mandible - upper or lower bony portion of the beak

Marek’s disease - a neoplastic disease affecting lymphocytes, causing skin lesions and tumours, and affecting the neural tissue causing paralysis.  Vaccination of 18-day embryos or chicks at hatching provides protection.  Viruses are the causative agents. 

Mash - feed ingredients ground into small particles and mixed to provide a complete diet.

Mate - Pairing a rooster with one or multiple hens, or the act of doing so. Often different types of fowl have different mating habits. Many domestic ducks and chickens will mate with many different females in a flock, but often a gander will only mate with between 1-4 specific geese. Many of the rarer wild adult ducks we sell are sold as "Mated Pairs" because in the wild they are generally monogamous for at least one mating season. Some ducks and geese are monogamous for life, and there are instances where the death of a mate can traumatize the other to the point where nothing can reasonably console them.

Maternal - pertaining to the mother.

Maternal antibodies - antibodies of the hen that are transferred to the chick through the egg yolk.

Mating ratio - the number of females mated to one male.  It varies with age, breed and species.  The common ratio in chickens is 1 male to 6 to 12 females

Meat Breeds - usually in reference to a broiler or fryer, these are breeds that have utility of good meat production as either their main or secondary utility trait.

Mechanical transmission - disease causing agents carried on a surface (such as shoes, tires, shovels, etc.)

Meckel’s diverticulum - the remnant of the embryonic yolk sac attachment to the small intestine.  It is used as a marker indicating the end of the jejunum and start of the ileum.

Meconium - the greenish faecal material forming the first bowel movement of the newly hatched chick.

Medial - toward the middle or midline of the body.

Membrane - a thin, soft, pliable layer that normally separates two different types of tissues.

Metabolism - the physical and chemical processes that produce and maintain a living body

Mite - a type of external parasite

Molasses - a thick, dark syrup produced during sugar refining or from sorghum or other sources that can be used as a feed ingredient.

Molt (Moult) – the part of a hens ( mostly) yearly cycle when she stops laying and changes some or all of her body feathers

Mongrel - mixed-breed bird resulting from indiscriminate mating

Morbidity - a health problem of a bird that typically requires it to be put down. Percentage affected by a disease.

Mortality - death due to disease or accident. Percentage killed by a disease.

Mossy - indistinct, irregular, or messy-looking markings that break up or destroy the intended colour pattern on feathers

Mottled - plumage where a percentage of feathers are tipped with white; a discoloration of egg yolk caused by damage to the yolk membrane

Muff - fluffy feathers on the face of chickens (tufts are feathers that protrude from the face)

Mounting - when the rooster mates with a hen

Mushy chick disease or omphalitis - an abdominal or navel infection of chicks acquired during the hatching process.  Controlled by strict sanitation in the hatchery, incubators and hatchers.

Mutation - a sudden permanent variation in an inherited character of an animal.

Mycoplasmosis - diseases caused by various types of Mycoplasma, which are organisms smaller than bacteria and larger than viruses and that lack a cell wall.  Mycoplasma gallisepticum, M. synoviae and M. meleagridis are the most common and are egg transmitted.  Controlled mostly by eradication and prevention.

Mycosis - a disease caused by a fungus.

Mycotoxicosis - effects due to mould toxins from one or more mould species.  Common toxins are aflatoxin, ochratoxin and T-2 toxin.

Myoglobin - an iron-containing protein, similar to haemoglobin that is found in muscle and influencing muscle colour as well as supplying oxygen.


Nares - the external opening of the nostrils.

Necropsy - a post-mortem (after death) examination of an animal (equivalent to a human autopsy)

Necrotic - pertaining to dead tissue

Nematode - a roundworm

Nest - place with sufficient bedding that is secluded enough for a hen to feel safe laying and leaving an egg.

Nest egg - artificial egg placed in a nest to encourage hens to lay there

Nesting behaviour - in domestic chickens this involves a period of investigating nests, selection of a nest, oviposition, and exit from the nest, often followed by cackling for a short time.

Nestling - a young bird still in the nest.

Nest run - ungraded eggs

Newcastle disease - a respiratory and nervous system disease caused by various strains of a paramyxovirus.  Commercial birds are vaccinated multiple times and with different virus strains for prevention of the disease. This is a notifiable disease in most countries requiring destruction of the flock.

Neural - pertaining to the nerves

Nictitating membrane – Sometimes called the third eyelid. A transparent third eyelid in birds that blinks to keep the eye clean and moist.  The upper and lower eyelids remain open when the bird is awake.

Northern fowl mite - an arachnid parasite, very small, that lives on the bird and often is found in higher concentrations among the feathers of the abdominal area.  It lives on the blood of the bird.

NPIP - National Poultry Improvement Plan.

Nuptial plumage - plumage of the male just before and during the breeding season.

Nutritional encephalomalacia - “crazy chick disease” caused by a vitamin E deficiency.


Omphalitis or mushy chick disease - navel and abdominal infection in the young chick.  Prevented by strict sanitation in the hatchery and breeder farm.

Ontogeny - the life cycle of an individual

Oocyan - the pigment in some green- and blue-shelled eggs.

Oocyst - the starting and ending stage of the life cycle of coccidia.  An encapsulated form that is very resistant to the environment.

Oocyte - an ovum that has not begun the growth and maturation process.

Oogenesis - the process of formation of ova in the ovary.

Ocular - pertaining to the eye

Oesophagus - the portion of the digestive tract that moves from the mouth to the stomach

Oil sac - large oil gland on the back of birds at the base of the tail and used by the bird to preen or condition feathers (also called the uropygial or preen gland)

Oocyst - infective fertilized egg of certain one-celled animal parasites including protozoa.

Open beak – malformation that prevents the bird closing its beak properly.

Organic - a legalized regulated term related to production of food products according to pre-set standards

Ornithophobia - Ornithophobia is a type of specific phobia, which is an abnormal and irrational fear of birds. The origin of the word ornitho is Greek (meaning bird) and phobia is Greek (meaning fear).

Ornamental breed - a type of bird bred for appearance and show rather than for economic traits. 

Osteomyelitis - inflammation of the bone marrow.

Osteoporosis - thinning and weakening of the bones.

Outcrossing - Outcrossing or outbreeding is the practice of introducing unrelated genetic material into a breeding line. It increases genetic diversity, thus reducing the probability of an individual being subject to disease or reducing genetic abnormalities. The outcrossing breeder intends to remove the traits by using new blood.

Ova - female germ cells that become eggs.

Ovary - a part of the female avian reproductive tract which holds the female genetic material and collects the yolk material normally associated with eggs

Oviduct - a part of the female avian reproductive tract where the egg white (albumen), shell membranes, shell and bloom (cuticle) are added to form a complete egg.  It is a tubular organ and the anterior end is attached to the body wall near the ovary and the posterior end terminates at the cloaca.  It functions to pick up the ovulated ovum and to deposit albumen, egg membranes and egg shell around the ovum. 

Oviposition - the laying of an egg

Ovulation - the release of a yolk from the ovary

Ovum or ova (plural) - the female reproductive cell formed in the ovary, which consists of a very small genetic nucleus and a very large portion of nutrient yolk material all of which is enclosed in the thin vitelline membrane.  The genetic nucleus is seen as the germinal disc on the surface of the yolk and is that part combining with spermatozoa at fertilization.

Oyster shell - small pieces of the shell of oysters that can be used as a source of soluble grit and calcium for bone and eggshell formation.  When used, it is commonly fed as a separate supplement.


Pad or footpad - sole of the foot.

Pair bonding - development of fidelity between mated birds.

Palatability - the acceptability of a feedstuff to the bird.  Influenced by taste, smell, moisture, particle shape and texture, colour, and previous experience with the feedstuff.

Pancreas - a gland located between the duodenal loops of the small intestine.  It functions to produce insulin, glucagon, somatostatin and avian pancreatic polypeptides.

Panting - rapid and heavy breathing caused by high environmental temperature or physical exertion. 

Parasite - an organism that lives on or inside a host animal and derives food or protection from the host without giving anything in return.

Parrot beak - an abnormal development of the upper beak in which it is severely curved downward as the beak of a parrot or hawk.  Sometimes called hawk beak.

Pasting - Pasted vents - accumulation of diarrhoea-type faecal material or thick urine around the cloacal opening (vent), especially in young chicks, that is usually associated with disease or mismanagement loose droppings sticking to the vent area

Pathogen - disease-producing organism.

Pathogenic - able to cause disease.

Pathogenicity - the degree to which an organism is able to cause a disease.

Pathology - the study of damage caused by disease.

Pea Comb - a relatively small, low-set comb that is dominant to Single Comb.  It is present in some of the original breeds used for meat production stocks and has been found to be associated with lower fertility. Ameraucanas or the Light Brahma Chickens.

Pecking order - the social rank of individuals within a flock Pecking Order: The social ranks within a flock of chickens. This is often determined when the chicks are juvenile and may consist of a few brief "squabbles", until a clear "alpha chick" is decided. Males and females usually have separate hierarchies.

Peachick - a young (baby) peafowl.

Peacock - an adult make peafowl.

Peafowl - birds of the genus Pavo.  The most common domesticated peafowl has very large, colourful tail feathers that the male displays. 

Peak production - the point in the egg production period when the rate is at its highest.

Peahen - an adult female peafowl.

Peck - strike or pick up with the beak or bill.

Peep(s) - a term for chick sometimes used by small flock owners.

Pectoral muscles - the two large muscles of the breast; flight muscles.  The large superficial pectoralis major is responsible for drawing the wing downward whereas the smaller deep pectoralis minor is responsible for raising the wing during flight.

Pedigree breeding - a method of selecting breeding stock on performance, which may include the performance of ancestors, siblings and progeny.

Pelvic girdle - consists of hip bones and sacral bones and includes the ilium, ischium and pubis bones.  The bottom of the girdle is open and will expand when the bird is in egg production.

Pellets - feed that has been compressed into small, rounded particles.  Steam (heat) is used. 

Pen - group of chickens entered into a show and judged together or the outside area around a coop.

Pencilled - crosswise lines on feathers that form a pattern, as in silver pencilled Wyandotte.

Pendulous crop - a crop that is impacted and enlarged and hangs down in an abnormal manner. May be the result of poor diet or old age and can be fatal.

Perch – or roost - A bar, normally of wood or plastic where chickens can get off the floor of the coop to sleep or rest. The natural behaviour of chickens is to roost in trees and they are well adapted to gripping round branches.

Performance - an economically important, measureable trait of a bird or flock.

Pericardium - the membranous sac surrounding the heart.

Peristalsis - rhythmic, wavelike muscle contractions of the intestinal tract that move the contents through the tract.

Peritoneum -the membranous lining of the abdominal cavity.

Peritonitis - an inflammation of the peritoneum

Perosis - malformation of the hock joint

Persistency – of lay the ability of a hen to lay eggs steadily over a long period of time. Hybrids are selectively bred for this purpose.

PH - a number that indicates acidity or alkanity (7 is neutral, above 7 is alkaline and below 7 is acid)

Phallus - the terminal reproductive organ of the male bird that consists of grooved phallic folds.  Size and structure varies with species.

Pheasant - gamebird that comes in many breeds and varieties that originated in many different regions of the world. Often they are raised and hunted for their food and sport (Ring neck Pheasant), and many breeds of pheasants are raised for ornamental purposes

Pick out - vent damage caused by other chickens' pecking

Pigeon milk - a cottage-cheese looking crop substance produced by both the male and female pigeon to feed the young from hatch till about 10 days of age

Pigmentation - the colour of a chicken's beak, shanks and vent

Pinion - The surgical removal of the point of the wing at the outer joint. Done to permanently prevent the bird from being able to fly.

Pip, pipped, pipping - the act of breaking through the shell by an embryo during the hatching process.  An internal pip is an embryo that has pierced the membranes into the air cell but has not pierced the shell (external pip). Pin bones - pubic bones

Pin feathers - a developing feather on a bird

Plumage - the total set of feathers covering a bird

Post (as in after) - to conduct a post-mortem (after death) examination

Poulet de Bresse - a specialty meat chicken raised in the Bresse region of France having coral-red combs, white feathers and blue legs.  They are range-reared until the last two weeks when they are confined and fed white corn and whole milk.

Pluck - to pull feathers from the skin.  May be referred to as pick or picking.  Usually done by machine following dipping the dead bird in hot water.  Waterfowl may be dipped in hot wax to make plucking easier.

Plumage - the feathers or feather covering of a bird.

Plumules - soft downy feathers or under feathers.

Plymouth Rock - a large breed of chicken of the American Class that is one of the base stocks for meat type commercial birds.

Pores (of shell) - very small tubes or holes in the eggshell from the exterior surface to the interior surface.  Their shape, size, branching, number and distribution vary with species and strains.  The primary function is exchange of gases such as oxygen and carbon dioxide as well as water vapour.

Poult - young (baby) turkey or pheasant.

Poultry - a term for domestic fowl raised for meat, eggs, feathers, work or entertainment.

Preen gland - an oil sack on the back and near the base of the tail of birds providing oil used in preening (also called the oil or uropygial gland).

Primaries - large wing or flight feathers (remiges) that are attached in the metacarpal and phalangeal area (hand) of the wing.  There are approximately 10 in the chicken, but may vary with species.  The proximal end of the feather is protected by smaller feathers or coverts.

Primary host - an animal in which a parasite completes its life cycle.

Primitive streak - an early development stage of the avian embryo that appears after approximately 6 to 8 hours of incubation.

Preening - to straighten and clean feathers, typically with oil secreted from a gland at the base of the tail.

Placings - ranking of birds or products during judging contests.

Plasma - the fluid, including clotting constituents, remaining after cells have been removed from blood.

Preferential mating - in a flock a male may mate many times with some females but few times or none with other females, thus contributing to infertility.

Prolapse - when there is vent damage, typically caused by laying a very large egg (also referred to as a blowout).

Proventriculus - the true stomach of birds where pepsin and acid are produced.

Pubic bones - two bones that end in front of the vent of birds.

Pullet - immature female bird (used with several species of birds, but most commonly with chickens).

Purebred - offspring from a pair or flock of the same breed and having measurably similar characteristics.


Quail - small gallinaceous game birds of various types found on most continents.  The Bobwhite, native to North America, has economic value for meat and hunting.  Several other types of quail are also indigenous to North America.  Coturnix or Japanese quail have economic value for both meat and egg production.  Coturnix are migratory, Bobwhite are not.

Quarantine - the maintenance of birds in isolation for a specified period of time to determine if they have an infection, to prevent the spread of infection, or other purpose in the biosecurity system of a poultry operation.

Quaternary ammonium compounds - a group of chemicals commonly used in poultry operations as disinfectants.

Quill - the hollow base portion of large, mature feathers.  It contains a blood supply in the growing feather and the tip is embedded in the feather follicle of the skin.


Rachis - the portion of the feather shaft having barbs and barbules

Rales - any abnormal sounds coming from the airways of birds, mostly caused by illness or parasites but can happen after prolonged exposure to pneumonia in an unventilated dirty coop.

Range Fed - Similar to free range, this describes poultry that are allowed to graze freely.

Ration - a combination of feed ingredients formulated to meet a bird's nutritional requirements. Ration:  the amount of feed allowed per day or time period

Ratite - a type of domestic bird that does not have a keel bone and includes ostriches, emus and rheas

Recessiveness - the allele in a heterozygote that is suppressed by its partner and is expressed only in the homozygous state.

Reciprocal mating - crossing two strains or groups in two ways, i.e., A males with B females and B males with A females.

Red mite - an arachnid parasite, very small, that feeds on the blood of the bird at night but does not stay on the bird during the day.

Relative humidity - the amount of moisture in the air compared to the maximum that it could hold at that temperature.  Usually expressed as a percentage.

Renal - anything pertaining to the kidneys

Render - the process by which slaughter by-product are treated to convert them into protein products for use in animal feeds

Rhea - large non-flying ratite bird of South American origin, smaller than ostrich and emu, which is sometimes used for meat production.

Rhode Island Red - base stock of chickens of the American Class used for commercial production of brown eggs as well as being useful stock for home flocks.

Rickets - abnormal bone growth resulting from dietary deficiencies or imbalance of vitamin D, calcium and phosphorus.

Ridge ventilation - an opening is left at the peak or ridge of the roof allowing warm air to passively rise out of the house.  Fans may be placed in a closed-ridge roof to provide forced ridge ventilation.

Rigor mortis - stiffness following death.

Roach back - deformed, hunched back which is a disqualification when showing poultry. Birds with this condition should never be bred from or shown.

Roaster - a meat-type chicken raised to a size that makes them suitable for roasting.

Roost - a place where chickens can get off the floor away from ground based predators.

Rooster – adult male chicken.

Rose comb - type of small, compact comb that is dominant to single comb. With a flat top, this comb is solid and broad set low on the chicken’s forehead. The shape of the rose comb varies in different breeds, and can sometimes be pointed more upwards than straight back. Silver Laced Wyandotte.

Roundworm - Ascaridia galli is one of the most common poultry worm parasites.  Generally found in the central part of the intestine.  Worm infestations have been reported to be associated with reduced allergenic reactions. 

Run -   an area outside of the house to allow outdoor activity.

Rumpless - genetic trait or mutation in some chicken breeds where they have no tail, like the Rumpless Araucanas or in the UK, the Rumpless Game.


Saddle - a part of a bird's back from behind the neck up to just before the tail.

Sanitize - to clean and disinfect in order to kill germs

Sanitation - maintaining healthful and disease free conditions through cleanliness, treatment of the environment with anti-microbial agents, prompt removal of wastes and other preventative measures.

Scales - small, hard, overlapping plates that cover a chicken's shanks and toes.

Scaly leg - scales on the legs and feet may be raised with encrustations.  Caused by a type of mite (arachnid) that burrows under the scales.  Can be controlled by treatment with oils.

Scald - dipping birds in hot water (approximately 128 to 140°F) for a specific time to loosen feathers for plucking.

Scratch - the habit of chickens to scrape there claws against the ground to dig up food items;

Scratch feed - whole grain, cracked grain or pellets that are scattered on the litter or ground in some feeding systems, especially small poultry units. A term used for any whole grains fed to chickens

Seasonal breeder - a bird that is in an active reproductive state during a specific season of the year.  Commonly respond to light as the determining factor, however, temperature, rainfall, food availability and other factors may be the primary determinant.

Sebum - the oily substance secreted by the uropygial gland and a few sebaceous glands

Secondaries - a second group of large wing flight feathers located nearer to the body than the primaries and which cover the primaries when the wing is normally folded.

Secondary sexual characteristics - differences between females and males such as feather colour and shape, comb size and shape, pubic bone separation, body size, behaviour and voice that come on as the bird ages.

Second cycle hens - laying hens that have been force-rested and are in the post-rest or post-moult laying period.

Serology - Tests on blood serum to determine the level of circulating antibody to specific disease agents.

Set - To brood or sit on eggs to keep the warm for hatching. Place eggs in incubator.

Setting – The placing of egg under a hen or in an incubator.

Setter - the incubator or incubation machine in which eggs are placed for incubation for approximately 18 days (chicken) prior to moving to a hatcher.

Sex – gender.

Sex chromosome - the pair of chromosomes (Z and W) that determine the gender of the individual.  In the bird the female is the heterozygote (ZW), thus determining gender of the offspring, whereas the male is the homozygote (ZZ).

Sexing - determining the gender of a chick (or older bird) by examination, feather, colour, feather length, instrument, cloacal examination or DNA. 

Sexing scope - an instrument similar to a proctoscope used to view the testes through the large intestine wall to determine gender of the chick.

Sexed chicks - day-old chicks that are separated into separate groups of male and female chicks.

Sex-feather - the curled feather on the tail of male ducks.

Sex feathers - rounded hackle, saddle, and tail feathers on a hen; pointed hackle, saddle and tail feathers on a rooster.

Sex-linked - an inherited factor linked to the sex chromosomes and used in developing specific crosses to make sexing day-old chicks easier.

Sexual maturity - the age at which the female first lays an egg and the male produces semen that is capable of fertilizing an egg.  Varies widely among domestic species (e.g., 7 to 8 weeks of age for Japanese quail and 28 to 30 weeks for turkeys).

Shaft - part of the feather where the barbs are attached.

Shank - the part of a bird's leg between the foot and the hock.

Showgirl – a naked neck silkie.

Sheen - the lustre, glossy or glistening effect seen on the feathers, often appearing green or purple and influenced by lighting.

Shell gland - the portion of the female avian reproductive tract where the shell is added to the egg (also called the 'uterus').

Shell membrane - consists of two membranes.  The outer membrane lines the inner surface of the shell, whereas the inner membrane surrounds the egg albumen.  A space may form between the membranes at the large end of the egg, which is called the air space or air cell that has an important embryonic function in the hatching process. 

Short day - a day length that is insufficient to stimulate hormone release and gonadal growth.

Siblings - brothers and sisters.

Sickles - long, curved tail feathers of some roosters

Side sprig - projection from the side of a single comb (a disqualification when showing single-comb breeds of chickens)

Silkie - the type of feather characteristic of the Silkie breed in which the barbs of the feathers are not locked together thus giving the feather a fluffy texture.

Silver and gold - plumage colours in which Silver is dominant to Gold.  The alleles are sex-linked and can be used as auto-sexing characters to determine the sex of the chick at hatching.

Single Comb - This is the most commonly portrayed and recognized comb in most chicken images and artwork. The Single Comb is thin with a smooth textures, and it has a large base reaching from the base of the beak to the back of the head. The comb points upward is usually defined by five or six deeply serrated points. The male chickens typically have much thicker and larger combs. The combs always stand upright in males and can be upright or lopped over in females. See the Barred Plymouth Rock or the White Leghorn Chicken. It is recessive to Rose and Pea Combs.

Sire - Father.

Sire family - The offspring of one cock mated to two or more hens, so that all are full or half siblings.

Smut - Black feathers that are uncharacteristic for the breed, such as black body feathers in a Rhode Island Red.

Snood - the flap of skin that hangs over the turkey's beak.

Spent (as in a spent hen) - a hen that is no longer laying eggs.

Sperm - the male reproductive cells capable of fertilizing the ova from the female.

Spike - round extension found at the end of a rose comb.

Splayed legs - the legs are positioned such that the bird is unable to stand up (also called 'spraddle legs').

Spur - the sharp horny protrusion from the back of a bird's shank (typically larger in males than in females).

Squab - a young (baby) pigeon that has not yet left the nest; also refers to pigeon meat since pigeons are usually marketed before they leave the nest.

Squeaker - a young pigeon still in the nest.

Squirrel tail – a very high set tail in show birds that has more than a 90 degree angle. This is a vertical fault unlike a wry tail which is bent to one side or a split tail.

Squat or squatting - position in which the hen crouches close to the ground in accepting the approach of a male for mating.

Stag - A cockerel on the brink of sexual maturity, when his comb and spurs begin to develop.

Standard - description of an ideal specimen for its breed or a chicken that conforms to the description of its breed in the American Standard of Perfection. Sometimes erroneously used when referring to large as opposed to bantam breeds.

Started pullets - female chickens that are nearly old enough to lay.

Starter - feed ration for newly hatched chicks, also called "crumbles". Or chick crumb in the UK.

Starve-out - a chick that has not eaten. Also happens when battery rescue hens are demobbed and not fed.

Sterile - permanent inability to reproduce.

Sternum - breastbone or keel.

Straight bred - Purebred.

Straight-run – unsexed day-old chicks that have not been sorted.

Strain - a group of birds within a variety of a breed that has been bred by one person or company for generations.

Strawberry Comb - very low set comb hanging over the top of the beak. The shape and surface resemble the skin of a strawberry, and it is wider closer to the beak of the bird.

Stress -  responses of the animal that include increased adrenal hormones, immunosuppression, decreased reproduction or growth and numerous other physiological reactions to factors or stressors such as disease, malnutrition, adverse environments, noises, crowding, injury, etc.

Strutting - a part of the courting behaviour of male turkeys, often accompanied by trumpeting vocal calls.

Stub - down on the shank or toe of a clean-legged chicken. Mostly a minor fault.

Sunken eye – Fault in chickens where the eye is set deep into the skull causing a half closed look. Can be the result of illness.

Syndrome - a group of symptoms that occur in combination in a particular disease.

Synergistic - working in cooperation.


Tapeworms, cestodes - flat, white, ribbon-like, segmented parasites of the intestine.  Require an intermediate host such as earthworms.

Testes - the male reproductive glands (located internally in birds).

Tendon - tough, fibrous connective tissue connecting muscles to bone or other tissue.

Thick albumen - the third layer of albumen out from the yolk.  It is heavy, thick and contains many mucin fibres giving the albumen shape; it is attached to the inner shell membrane at both ends of the egg. 

Thigh - the upper leg, with femur bone, between the knee and the body (pelvic girdle).

Thin albumen - two layers of albumen (the inner thin is between the cheliferous and thick albumen layers and the outer thin is between the thick albumen and the inner shell membrane around the equatorial area of the egg) that contain few mucin fibres. 

Tin hen – the slang term for an incubator

Tom - an adult male turkey (also referred to as a 'gobbler').

Torpidity - dormant or inactive; sluggish metabolism and activity.

Torpor - the state of being dormant or inactive.

Torticollis - twisted or wry neck.

Toxaemia - toxins, usually from micro-organisms, have been absorbed and are in the blood.

Toxin - a poison produced by microorganisms.

Trachea - the windpipe.

Trap nest - a nest used in pedigree breeding which holds the hen until identified and released.

Treading - mounting of the female by the male during mating.

Trematodes - leaf like flatworms (flukes) that may afflict various parts of the body but are not usually a serious problem.  Require snails as an intermediate host.

Tremors - Encephalomyelitis.

Trussing - tying the wings and shaping poultry before cooking.

Tumour - a swelling or abnormal growth that may be benign or malignant.

Tunnel ventilation - a closed house having forced ventilation with air inlets in one end of the house and outlets at the other end.  In positive pressure houses the fans are in the inlets pushing air into the house.  In negative pressure houses the fans exhaust air from the house.  Generally, a negative pressure system is used in commercial poultry houses.

Turning (of eggs) - eggs are turned in nature by the brooding bird and in incubators by automatic turning mechanisms.  Eggs are normally turned one to four times per hour from setting until 18 days of incubation (chicken).  The most crucial time seems to be from two to seven days.  The ideal frequency, angle and embryo age for egg turning may vary with species, strain, breeder age, type of machine and other factors.

Trematode - A parasitic fluke.

Trio - a male with two females of the same species, breed and variety. In the UK this is one way birds are sold at auction.

Turkey - A large game bird that is native to North and South America. There are a few varieties of Wild Turkeys, Commercial Meat Turkeys, as well as domesticated Rare or Heritage Breed Turkeys. Domestic turkeys are very large, cannot fly and are artificially inseminated on a commercial basis.  They produce a high percentage of white (breast) meat.

Type - the size and shape and characteristics of a chicken that identifies the breed. i.e. The Barred rock is true to type.


Umbilicus - the place where the blood vessels supplying the embryonic membranes pass through the body wall.  Just prior to hatching the yolk sac is withdrawn into the abdominal cavity and the umbilicus closes and heals as the vessels to the other membranes dry up. The opening to that part of the feather calamus embedded in the feather follicle is known as the proximal umbilicus whereas the opening in the feather shaft at the junction of the calamus and rachis is the distal umbilicus.

Unabsorbed yolk - the yolk material remaining in the withdrawn yolk sac at hatching.  After hatching it moves directly into the small intestine and is quickly absorbed.  The stalk attaching the yolk sac to the intestine remains in the older bird.  It is called Meckel’s diverticulum and is thought to have some immune system functions.

Undercolour – The base colour of the down feathers.

Unsexed - day-old chicks that have not been sorted by sex. Straight-run in the USA.

Urates - uric acid. Pee. The avian form of urine that is often seen as a thin white paste with the faeces.

Uraemia - poisoning caused by accumulated wastes in the body, more often than not caused by kidney failure and the inability to excrete wastes.

Uropygial gland - large oil gland on the back and at the base of the tail of birds providing oil for the birds to preen their feathers (also called the preen or oil gland).

Utility - for our purposes we use the word utility to describe a breed of poultry in terms of its production or value on a farm, such as egg, meat, or pest control.

Uterus - the section of the female avian reproductive tract where the shell is added to the egg (also known as the 'shell gland').


V-Shaped Comb - made up of two well-formed horns that are joined at the base to form a V-shape. This is one of the most unique and interesting of all comb shapes. Crevecoeur and Polish Chicken.

Vaccine - Product made from disease-causing organisms and used to produce immunity.

Vagina - the section of the female avian reproductive tract where the bloom/cuticle is added to the egg just prior to being laid.

Valgus - an abnormal condition in which the legs are bent or twisted outward.

Vane - the part of a feather consisting of barbs, barbules and barbicels that forms the wide portion of the feather on either side of the shaft or rachis.

Variety - subdivision of a breed, according to plumage colour, comb type, etc. So a Silver Laced Barnevelder would be a good example of a different variety of Barnevelder.

Vector - the means by which a disease is spread.

Vent - the common outside opening of the cloaca in birds through which the digestive, excretory and reproductive tracts empty.

Vent sexing - a procedure for determining the sex of newly hatched poultry by examination of the cloacal anatomy.

Ventral - the underneath portion of the body as opposed to dorsal or back.

Vertebrae - bones in the spinal column.

Vertical transmission - disease transmitted from parent to offspring through hatching eggs.

Viability - ability to live and develop.  See Mortality.

Vices - bad behaviours that include but aren’t limited to cannibalism, feather pulling, toe-pecking, egg eating, flightiness, hysteria.

Vitelline membrane - the non-cellular membrane that surrounds the yolk material and blastoderm of the egg yolk.  Two inner layers are ovary-derived and 2 outer layers are oviduct-derived.  The outer 3 layers are coatings on the inner layer, which is the vitelline membrane.

Virus - very small microscopic agents causing diseases including Infectious Bronchitis, Newcastle Disease and Fowl Pox.  Capable of multiplying only inside a living cell.

Viscera - the organs and tissue within the abdominal and thoracic body cavities.

Virulence - the level at which a disease-causing organism is able to cause a disease.

Vulture hock - feather-legged breeds where the feathers grow off the shank and touch the ground.


Waltz - a common part of the courting behaviour of male chickens.

Walnut Comb - this comb is a roundish and lumpy comb that is usually wider than it is tall. These will vary from breed to breed, and some generally like to think of it as a rose comb plus a crest. Like the Silkie. Small type comb resulting from the presence of rose and pea genes.  Interbreeding can give birds with walnut, pea, rose or single combs.

Waterfowl -   swimming birds that this includes ducks, geese and swans.

Water glass - sodium silicate when mixed with water forms a clear, thick liquid that historically was used to preserve eggs.

Wattles - the flap of skin under the chin of a chicken or turkey.

Web - the network of interlocking parts that give a feather its smooth appearance; a part of the feet of waterfowl.

Wet-Bulb Temperature - Temperature measured by a standard thermometer equipped with a wet sock over the bulb. A lower wet bulb temperature indicates the incubator is dry, as there is so much evaporation of water off the sock that the thermometer is cooled. If the wet bulb temperature is close to the dry bulb temperature, it indicates that the incubator is very humid as there is very little evaporative cooling from the sock. Instead of buying a wet bulb sock, you can use a hollow shoe lace.

Wing - the forelimb of the bird.  Developed for flight in most birds whereas in others it is used for swimming or balance in running.

Wing band - a metal or plastic identification tag fastened to the wing web or around the upper wing or humerus (wing badge).

Wishbone -  a common name for the v-shaped clavicle bone in the breast.

Withdrawal diet - the diet fed to birds for a specified time prior to slaughter and contains no antibiotics or other compounds that might be undesirable in the meat for human consumption.

Wind egg - wind egg is the colloquial name for a fully formed egg that does not have a yolk in it

Wing clipping - a procedure in which the primary wing feathers of one wing are cut to prevent flight

Whiskers - muffs.

Whites – the egg white

W.O.G. - Without giblets

Wry tail - tail that lays to the left or right side and is not symmetrical with the body line


Xanthophyll’s - the yellow pigments found in leaves, grasses and green plants that are added as pigment to avian skin as well as providing the yellow colour of egg yolks

Yolk - the round yellow mass upon which the genetic material of the female (and male if the egg is fertilized) is located and that provides nutrients for the developing embryo

Yolk sac - the membrane that surrounds the yolk in the incubating egg


Zoning - laws regulating or restricting the use of land for a particular purpose such as raising poultry

Zoonosis - a disease transmissible from an animal to a human (plural = zoonosis)

Zygote - the fertilized egg before development (cleavage) begins.  Fertilization occurs in the infundibulum of the oviduct