Glossary

43 terms every poultry breeder and exhibitor runs into — from candling to grand master points.

Incubation & hatching

Candling: Shining a bright light through an egg to see inside — used to confirm fertility (a web of blood vessels), track the air cell, and spot clears and quitters. Named for the candles originally used.
Lockdown: The final stage of incubation (day 18 for chickens) when you stop turning the eggs, raise humidity, and keep the incubator closed so hatching chicks aren't shrink-wrapped by a drop in humidity.
Air cell: The pocket of air at the large end of an egg. It grows as the egg loses moisture during incubation; its size is the best real-world gauge of whether humidity is right (aim for about one-third of the egg by lockdown).
Pip: The first break a hatching chick makes. An internal pip is when it breaks into the air cell and starts breathing; an external pip is the first crack through the shell.
Zip: When a hatching chick turns inside the shell and cuts a ring around it with its egg tooth, 'unzipping' the top to push out.
Egg tooth: A small, temporary hard point on a chick's beak used to pip and zip the shell. It falls off within days of hatching.
Dry hatch: An incubation method that runs lower humidity through most of incubation and relies on watching the air cell grow to the right size, then raising humidity at lockdown. Common in humid climates.
Forced-air incubator: An incubator with a fan that circulates air so the whole cabinet is one even temperature. Set chicken eggs to about 99.5–100°F.
Still-air incubator: An incubator with no fan, so warm air layers near the top. Temperature is measured at the top of the eggs and run higher (about 100.5–102°F for chickens) than a forced-air unit.
Clear: An egg that shows no development on candling — either infertile or with very early embryonic death. Removed during incubation so it doesn't spoil.
Blood ring: A ring of blood visible on candling that indicates an embryo started to develop and then died, leaving the blood vessels to detach into a circle. A type of quitter.
Quitter: An egg whose embryo began developing but stopped. Removed on candling so it doesn't rot and contaminate the incubator.
Staggered hatch: Having eggs at different incubation stages in one incubator, so hatch days don't line up. It complicates lockdown humidity because opening the incubator for one hatch affects the others.
Brooder: The warm, safe enclosure chicks move to after hatching, with a heat source, bedding, food, and water.
Autoturner: A motorized incubator tray that turns eggs automatically several times a day, replacing hand-turning until lockdown.
Wet-bulb temperature: A humidity measure some incubation guides use: the reading from a thermometer with a wet wick over the bulb. Lower wet-bulb readings mean drier air.
Hatch rate: The share of eggs set that hatched. Often reported two ways: hatch of all eggs set, and hatch of fertile eggs — the second is fairer to the incubator because it excludes infertile eggs.
Fertility rate: The share of eggs set that were fertile, judged by candling or breakout. Separates breeding-pen problems (low fertility) from incubation problems (low hatch of fertile).

Breeding & genetics

F1 / F2: Generations of a cross. F1 is the first-generation offspring of two parent breeds; F2 is the result of breeding two F1 birds (or an F1 back to a parent). Central to olive-egger breeding, where egg color deepens across generations.
Oocyan (blue-egg gene): The dominant gene that deposits blue pigment (biliverdin) throughout the eggshell, so blue eggs are blue inside and out. Combined with a brown coating it produces green and olive eggs.
Olive egger: A cross between a blue-egg breed and a dark-brown-egg breed. The blue base plus a dark-brown coating yields an olive-green egg; the shade depends on how dark the brown parent lays.
Easter Egger: Not a breed, but any mixed-breed bird carrying a blue-egg gene. Easter Eggers can lay blue, green, or other colors and do not breed true — unlike a recognized breed such as the Ameraucana.
Breeds true: When two birds of a variety reliably produce offspring like themselves — the mark of an established breed and variety, as opposed to a random cross.
Split: A bird that carries a recessive trait without showing it. Its outward appearance is one thing, but it can pass the hidden trait to offspring.
Sport: A bird that shows an unexpected trait not seen in its parents, arising from a spontaneous change or a hidden recessive surfacing.
Line breeding: Breeding related birds within a family line to fix desirable traits, more loosely than close inbreeding. A common tool for improving a show strain over generations.
Breeding pen: A controlled group of birds — typically one male with selected females — set up to produce hatching eggs of known parentage.

Showing

APA class: A grouping used by the American Poultry Association to organize large-fowl breeds for judging (for example American, Asiatic, English, Mediterranean, Continental, and All Other Standard Breeds).
Variety: A subdivision of a breed, usually by color or pattern (and sometimes comb type). Birds are entered and judged by variety at a show.
Disqualification (DQ): A fault serious enough that a bird cannot be placed at a show — such as a defect specifically listed as disqualifying for its breed. Distinct from a lesser 'defect' that only costs points.
Coop-in / coop-out: The times exhibitors bring birds into their show cages (coop-in) and may remove them (coop-out). Leaving before coop-out is often penalized.
Champion Row: The display of top-winning birds at a show — the champions of each class competing for higher overall awards like Champion Large Fowl or Best in Show.
Grand Master points: Points accumulated by exhibitors over time under APA/ABA programs toward titles such as Master Exhibitor and Grand Master, based on wins across sanctioned shows.
Conditioning: Preparing a bird for show — washing, drying, cleaning legs and comb, and settling the bird to cage — so it presents at its best.

Birds & flock

Pullet: A young female chicken, generally under a year old.
Cockerel: A young male chicken, generally under a year old.
Hen: An adult female chicken, generally over a year old.
Cock: An adult male chicken, generally over a year old.
Straight run: Chicks sold unsexed, as they hatch — roughly half males and half females, with no sorting.
Broody: A hen's instinct to sit on and hatch a clutch of eggs. Broody hens stop laying and can be used to hatch and raise chicks naturally instead of an incubator.
Cull: To remove a bird from the breeding program. In breeder usage this can mean rehoming or selling as much as harvesting — the point is not to breed it forward.

Records & compliance

NPIP: The National Poultry Improvement Plan — a voluntary US program of testing and certification standards for poultry disease. Participation is commonly required to ship hatching eggs or birds across state lines and is used as a trust signal by sellers.
Pullorum-typhoid testing: Testing a flock for two bacterial diseases (pullorum and fowl typhoid), commonly part of NPIP participation and often required to enter birds at shows. Rules vary by state and program.