A poultry hatchery is a facility designed to incubate fertilized eggs and produce day-old chicks for commercial farms or backyard flocks. It sits at a critical point in the poultry supply chain, receiving fertile eggs from breeder flocks and delivering healthy, vaccinated chicks to the farms that raise them for meat or egg production. In modern poultry operations, the hatchery is typically owned by the same company that controls the breeder flocks, feed mills, and processing plants, making it one link in a tightly coordinated system.
Where Hatcheries Fit in the Supply Chain
Commercial poultry production is vertically integrated, meaning a single company owns and controls multiple stages of production. Breeder farms maintain parent flocks whose sole purpose is producing fertile eggs. Those eggs are collected, transported to the hatchery, and placed into incubators. Once the chicks hatch and are processed (sexed, vaccinated, counted), the company coordinates delivery to grow-out farms, where broiler chicks are raised for meat or pullets are raised to become laying hens.
This integration matters because timing is everything. Chicks need to reach the farm within hours of hatching, while they’re still absorbing the last of their yolk sac for nutrition. A delay of even a day can affect early growth and long-term performance. The hatchery’s schedule drives the rhythm of the entire operation, from when breeder eggs are collected to when farm houses are cleaned and ready for a new flock.
How Incubation Works
The core job of a hatchery is replicating the conditions a hen would naturally provide while sitting on her eggs, but doing it for thousands or millions of eggs at once. The two most important variables are temperature and humidity. In a forced-air incubator (the standard commercial type), the target temperature is 100°F throughout the incubation period. Relative humidity is held at 58 to 60 percent for most of the cycle, then raised to 65 percent or higher in the final days before hatching to keep the membranes soft enough for the chick to break through.
Incubation length varies by species. Chicken eggs take 21 days, turkey and most duck eggs take 28 days, and goose eggs need about 33 days. Quail are faster: Coturnix quail hatch in just 17 days, while bobwhite quail take 23.
Eggs spend roughly the first 18 days in a “setter” machine, where they’re slowly turned at regular intervals to prevent the embryo from sticking to the shell membrane. On day 18, chicken eggs are transferred to a “hatcher,” a separate machine where turning stops and humidity increases. This transfer point is called “lockdown,” and it’s the last time the eggs are handled before the chicks emerge.
Candling: Checking for Viable Eggs
Not every egg in the incubator contains a living embryo. Hatcheries use candling, shining a bright light through the shell, to identify and remove non-viable eggs at several points during incubation. For chicken eggs, candling typically happens on days 7, 10, and 14.
In the first week, a fertile egg will show visible veins spreading outward from a small dark spot (the developing embryo). An infertile egg looks clear with no veins at all. By day 14, a healthy embryo fills most of the egg and appears as a large dark mass. The last safe candling day is day 18, just before lockdown.
Several signs indicate an egg has died. A “blood ring,” a red circle visible inside the shell, means the embryo stopped developing early. Faded or broken blood vessels with no movement suggest a later death. Eggs that die late in development, sometimes called “late quitters,” may look dark but show no movement when candled. Any egg with a rotten smell is removed immediately, since it can explode in the incubator and contaminate surrounding eggs.
Vaccination Inside the Egg
One of the biggest advances in hatchery technology is in-ovo vaccination, delivering vaccines directly into the egg before the chick even hatches. This is done between days 17 and 19 of incubation, when the developing chick can absorb the vaccine through the fluid surrounding it.
The most common vaccine delivered this way protects against Marek’s disease, a highly contagious viral illness that can cause tumors and paralysis in chickens. Before automated in-ovo systems were developed in the early 1990s, every newly hatched chick had to be individually injected by hand. Modern injection machines can vaccinate up to 50,000 eggs per hour, with needles that are automatically cleaned and disinfected between each egg. This replaced an enormous amount of manual labor and made vaccination far more consistent.
Chicks that aren’t vaccinated in the egg receive their vaccines after hatching through spray, eye drops, drinking water, or injection. Many hatcheries use a combination, delivering one vaccine in-ovo and others by spray on the day of hatch.
What Happens After Hatching
Once chicks break out of their shells and dry off in the hatcher, they go through a rapid series of processing steps before being boxed and shipped. The entire post-hatch window is typically measured in hours.
Sexing
For layer operations, only female chicks are needed, so determining sex at hatch is essential. The two main methods are vent sexing and feather sexing. Vent sexing involves a trained technician examining the shape of a tiny internal structure called the copulatory organ. It’s difficult work because there are more than fifteen different shapes to distinguish between males and females. Feather sexing is much easier to learn: male and female chicks from certain specially bred strains have visibly different wing feather lengths at hatch. The catch is that this only works in strains that have been genetically selected for the trait. Most breeds don’t show any feather difference between sexes.
Counting and Boxing
Large hatcheries use automated chick counters that work at high speed while maintaining accuracy. Getting the count exactly right matters because farms are stocked at precise densities, and over- or under-counting creates management problems down the line. After counting, chicks are placed into ventilated boxes, typically 100 chicks per box, and loaded onto climate-controlled trucks for delivery.
Scale of Modern Hatcheries
A small hatchery might handle a few thousand eggs per week, but large commercial operations set millions. The equipment reflects this scale. Setter rooms hold rows of cabinet-style incubators, each loaded with trays of eggs. Hatcher rooms are separated to maintain different temperature and humidity settings. Automated systems handle the transfer from setter to hatcher, the vaccination process, and the sorting and counting of chicks after hatch.
Automation has steadily reduced the number of workers needed while increasing throughput. Sexing and vaccination lines are designed so fewer staff can process more chicks per hour, and automated counters eliminate the human errors that come with manually counting thousands of fast-moving, identical-looking animals. Even so, hatcheries still rely on skilled workers for tasks like vent sexing and quality checks that machines can’t yet replicate reliably.
Why Hatchery Conditions Matter
The conditions a chick experiences during incubation and in its first hours of life have lasting effects on its health and productivity. Even small deviations in temperature or humidity can reduce hatch rates, produce weaker chicks, or cause leg and organ problems that show up weeks later on the farm. Contamination in the hatchery, whether bacterial or viral, can spread to an entire flock before it ever reaches the farm.
This is why biosecurity in hatcheries is strict. Workers typically change clothes and footwear before entering, equipment is sanitized between hatches, and airflow is managed to prevent cross-contamination between rooms at different stages of the process. The goal is to deliver a chick that is healthy, properly vaccinated, and ready to thrive from the moment it arrives at the farm.