Male chicks born in the egg industry are killed within hours of hatching. Because they can’t lay eggs and don’t grow fast enough to be raised for meat, billions of male chicks are culled worldwide every year, typically on their first day of life. It’s one of the most routine and least visible practices in industrial food production.
Why Male Chicks Are Killed
Modern poultry farming has split chickens into two highly specialized types through decades of selective breeding. Layer hens are optimized for egg production. Broiler chickens are optimized for rapid muscle growth and meat yield. These are essentially different animals at this point, with distinct metabolic profiles that show up as early as embryonic development: broiler embryos consume more oxygen, grow faster, and hatch a full day earlier than layer embryos.
Male chicks born from layer breeds fall into a gap where they serve no commercial purpose. They’ll never lay eggs, and they grow far too slowly to compete with broiler chickens bred for meat. A dual-purpose hybrid cockerel can reach 2 kilograms by 9 weeks, but a male from a layer breed takes 13 weeks to hit the same weight while consuming significantly more feed. Broiler chickens, by comparison, reach market weight even faster. Raising male layer chicks for meat costs more in feed than the meat is worth, so the industry treats them as a byproduct to be disposed of.
How Culling Is Done
Two methods are standard across the industry. Both are approved by veterinary authorities in North America and Europe for use on chicks within the first 72 hours of life.
The first is maceration, which uses a high-speed mechanical grinder with rotating blades. Chicks are fed into the device and killed through immediate fragmentation. The American Veterinary Medical Association states that death by maceration in poultry up to 72 hours old occurs immediately with minimal pain and distress. It is, by the clinical definition, instantaneous.
The second is carbon dioxide gas. Chicks are placed into a sealed chamber filled with high concentrations of CO2, typically between 70% and 100%. In some systems the chamber is prefilled before the chicks are placed inside. In others, gas is gradually introduced at a controlled rate. Both approaches cause loss of consciousness followed by death. Gas killing is slower than maceration but avoids the visual severity of grinding, which has made it more publicly palatable.
What Happens to the Remains
Culled chicks don’t simply go to waste. A significant portion enters the animal feed supply chain. Before Germany’s ban on chick culling took effect, 40 to 50 million male day-old chicks were sold annually as whole-animal feed in that country alone. Zoos are major consumers: a 2021 survey of British and Irish zoos found that 92% used male day-old chicks as a diet staple for carnivorous and omnivorous species, from birds of prey and owls to meerkats and mongooses. Nuremberg Zoo alone fed more than 65,000 chicks per year to its animals. The remainder typically goes to rendering for use in pet food, animal feed, or fertilizer.
Countries That Have Banned the Practice
A handful of countries have moved to end chick culling through legislation, all of them requiring hatcheries to adopt in-ovo sexing or other alternatives.
- Germany partially banned chick culling starting January 2022, with the full ban taking effect January 2024.
- France banned the culling of male chicks in shell egg production starting January 2023, though exemptions exist for egg products and animal feed.
- Austria banned the practice in July 2022, with exemptions for chicks used as zoo feed or raptor food.
- Italy has passed a ban set to take effect January 2027.
- Brazil, the world’s fifth-largest egg producer, is moving toward a federal ban.
The Netherlands has voted on motions to prohibit chick culling but has not yet enacted binding legislation. No such ban exists in the United States, Canada, or the United Kingdom.
In-Ovo Sexing: Identifying Sex Before Hatching
The technology making these bans possible is called in-ovo sexing, which determines whether an embryo is male or female while still inside the egg. Several approaches exist. Some use near-infrared light to detect color differences in developing embryos. Others analyze fluid extracted from the egg for hormonal or genetic markers. MRI-based methods can assess the embryo’s developing anatomy. These established techniques are 97% to 99% accurate.
Newer, lower-cost methods are in development. One recent approach uses smartphone imaging and machine learning to predict sex based on the egg’s external shape, achieving up to 89% accuracy. While less precise, it requires no specialized lab equipment.
The critical detail is timing. Most in-ovo sexing is performed around day 10 of the 21-day incubation period. This matters because chick embryos are not believed to experience pain until approximately day 13. Male eggs identified before that threshold can be removed and repurposed (often as animal feed) without the welfare concerns associated with killing a hatched, conscious chick.
The cost is modest. In-ovo sexing adds roughly 1 to 3 cents per egg at retail in Europe, translating to 12 to 36 cents per dozen. For context, the cage-free premium in the U.S. already runs about a dollar per dozen, and surveys show 71% of egg buyers are willing to pay a premium, with the median willingness sitting just above 36 cents per dozen.
Dual-Purpose Breeds as an Alternative
Another approach sidesteps culling entirely by using chicken breeds where both sexes have economic value: hens lay eggs and roosters grow well enough to sell for meat. These dual-purpose breeds were once the norm before industrial specialization split poultry into layers and broilers.
Modern dual-purpose hybrids like the Lohmann Dual show promise. Their cockerels reach 2 kilograms by 9 weeks, compared to 13 weeks for standard layer males, and their carcasses are considered marketable. Traditional heritage breeds like the Rhinelander perform worse, taking 15 weeks to reach the same weight with poor feed efficiency.
The trade-off is that dual-purpose hens lay fewer eggs than specialized layer breeds, and their male counterparts still grow slower than broilers. Managing mixed-sex flocks also adds complexity, since chicks can’t be visually sexed until around 10 weeks, requiring broiler-style management for the entire group during that period. For now, dual-purpose breeds occupy a niche market rather than offering a scalable replacement for conventional egg production. The economics only work when consumers are willing to pay a premium for both the eggs and the meat.