Before They Hatch

Words by
Robert Yaman

If one of our ancestors were to walk into a modern supermarket, they would be shocked by its abundance. Meat, eggs, and dairy—which at various points in history have been scarce, expensive, or contaminated,—are now common, affordable, and safe.


An unintended consequence of this abundance, however, is a severe reduction in the welfare of animals within this supply chain. Modern animal agriculture hardly resembles our bucolic ideals of happy animals grazing in a field, producing eggs and milk for their owners in exchange for care and protection, and then donating their bodies at the end of their lives. Instead, it has developed in similar ways to modern industrial manufacturing, with every step of the process heavily optimized for economic efficiency. Most accommodations for animals’ well-being that don’t align with profit incentives are competed away.

Possible responses to the resulting decrease in welfare include eschewing animal products altogether or leaning into the small-scale farming practices described above. However, these solutions are not the most likely, feasible, or scalable. They are akin to calling for degrowth as a solution to climate change. A better solution would be to embrace technology, which could create the possibility of a more humane equilibrium.

Fertilized eggs going through an MRI-based in-ovo sexing circuit, developed by Orbem. Credit: Orbem—courtesy of Robert Yaman.

The poultry sector holds the clearest promise for technology to improve animal agriculture. Poultry accounts for 96 percent of land animals eaten by Americans, mainly because these animals are so small relative to other animals that are commonly consumed, such as pigs or cows. Broiler chickens weigh slightly more than six pounds on average, whereas a modern beef cow weighs more than 1,400 pounds.

Their small size, however, makes it more difficult to ensure the welfare of each individual chicken on a farm. Some poultry facilities in the U.S. house over five million chickens, whereas the largest cow feedlots rarely break 100,000. With that many animals on site, even the most competent operators struggle to guarantee that each one is free from hunger, thirst, pain, injury, or disease.

Fortunately, technology excels in areas where scalability is the key challenge. An example of how technology is positively shaping the poultry sector is at the interface between the hatchery, where chicks are born, and the farm, where they live out their lives. Here, a trio of technologies—in-ovo sexing, on-farm hatching, and in-ovo vaccination—hold the potential to make the poultry sector both more efficient and better for chicken welfare. All three of these technologies remove the need to handle and process live chicks on the day they’re born, instead allowing poultry producers to work with unhatched fertilized eggs. The hatchery of the future that adopts all three can forgo handling live animals entirely. But before we can learn how these technologies work, it is necessary to understand why they are needed in the first place.

The Current State of Farm-to-Table

Globally, we slaughter more than 80 billion land animals annually and catch and kill one trillion fish. These numbers rise each year as economic prosperity and food security increase. The vast majority of animals are sold into commodity markets where welfare accommodations that increase cost face immense competitive pressure.

Even if businesses want to do things better, the realities of markets have led to some shocking practices. A poll conducted by the social science research firm, Bryant Research, asked respondents whether they rated various standard agricultural practices as “Acceptable” or “Not acceptable.” 86.8 percent of respondents believed that beak trimming (the practice of cutting off the tips of each chick’s beak so they are less capable of injuring each other while stressed on the farm) is not acceptable, and 84.5 percent of respondents believed maceration (killing day-old chicks by grinding them up alive) is not acceptable.

While this may seem strange given how seldom farm animal welfare is talked about, favorable attitudes towards it are actually a consistent and reproducible finding that spans the political divide. A recent YouGov poll, for example, showed animal rights as the fourth most supported political cause (behind free speech, religious freedom, and racial equality), and second least opposed cause (only behind free speech).

Another somewhat surprising finding from social science literature is that almost half of consumers support “banning slaughterhouses,” a measure that would make meat almost completely inaccessible. Naturally, these results are highly determined by the framing of the question, but the consistency with which people express pro-welfare views points to a growing cultural shift. Although animal welfare is often considered a niche issue, there is widely spread public concern over the way farm animals are raised and the moral price we’ve paid for the abundance of our food.

Nowhere is the price for this abundance clearer than in the poultry industry. Every two years, more chickens are slaughtered than the number of humans that have ever lived. And with numbers this large, even small improvements in the average welfare of chickens have a substantial cumulative effect.

A great place to direct these improvements is at a chicken’s first few days of life, which are particularly challenging. The poultry supply chain begins with large genetics companies that maintain closely guarded, purebred lines of chickens. These animals are genetically optimized to produce food as efficiently as possible. Some genetics companies sell “layers,” optimized for egg production. Others sell “broilers,” which are optimized for the production of meat. The performance difference between these breeds is why chicken meat and eggs are so cheap today. In the 1950s, a typical chicken would lay about 150 eggs per year; modern layers can lay twice that number. Modern broilers can grow to be over four times the weight of a natural chicken in only 6-7 weeks.

To create a new flock of chickens, fertilized eggs are harvested from a breeding farm and transported to “hatcheries,” which are large facilities outfitted with incubators that tightly control temperature, humidity, and CO2 levels around the developing eggs. Modern incubators also tilt eggs back and forth to prevent the developing embryo from settling on the bottom of the egg, a role normally fulfilled by a nesting mother hen.

At the end of the 21-day incubation period, the eggs begin to hatch. The “hatching window,” which refers to the time between the earliest and latest hatching chicks, can be up to 48 hours. During this time, newborn chicks are kept inside the incubator, which is far darker, noisier, and dustier than any natural environment would be. They generally don’t have access to food or water during this time and subsist, instead, on their remaining yolk sac.

Once most of the eggs have hatched, chicks are removed from the incubator and then passed through a series of “processing” steps. One of the most important of these is sorting by sex, which is traditionally done by a skilled laborer who picks up and examines each chick by hand. Layer chicks are sorted to remove males, which cannot produce eggs. Genetic specialization between layer and broiler chickens means that layers are scrawnier and thus cannot be economically raised for meat. It follows that male chicks are unprofitable and, thus, are killed immediately, usually via maceration.

For broiler chicks, sexing serves a different purpose. Male and female broilers are both used for meat, but males generally grow to be slightly heavier. Separate sex rearing helps farmers meet strict requirements around the target weight of the birds by increasing the uniformity in slaughter weights within each single-sex flock.

Other processing steps may include vaccination and beak trimming. Each processing step requires handling by a human, which itself has been shown to cause substantial stress for newborn chicks.

The final step is transportation to the farm, which is another serious challenge for animal welfare. Trucks are designed to transport as many animals as possible and so often lack food, water, or climate control. Transport times are regularly more than 24 hours without breaks, and in unfavorable climates, this can be deadly. According to reporting in The Guardian, 20 million chickens die during transport each year in the United States

Even if companies try to prioritize welfare within this process, the reality is that poor management can sometimes lead to tragic cruelty and neglect. Undercover investigations conducted by animal rights organizations at hatcheries have found that sometimes chicks are accidentally crushed by mechanized processing equipment, or drown in scalding water from a cleaning machine. It’s difficult to incentivize better management since third-party animal welfare certifications, such as Certified Humane or Global Animal Partnership, only start once the chicks reach the farm.

Pre-Hatch Technologies

There is good news despite this grisly backdrop: The poultry supply chain is in the beginning stages of a transformation enabled by technological advances that point to a system that is more efficient and more likely to guarantee a better beginning of life for chicks. In-ovo sexing, on-farm hatching, and in-ovo vaccination optimize different parts of this supply chain by moving processing and transportation steps to before any eggs hatch.

In-ovo sexing

In-ovo sexing allows farmers to identify which eggs will hatch into males and which will produce females. Male eggs can then be removed and destroyed before they can feel pain so that only female chicks are hatched. This technology has the potential to spare 6-7 billion day-old male chicks from needless death globally each year.

Two broad approaches for in-ovo sexing already exist and have reached commercial scale. The first of these approaches utilizes imaging technologies like MRI or hyperspectral imaging to look “through” the shell of the egg to determine the sex of the embryo inside. The second approach involves taking a small fluid sample from inside the egg, and then running PCR to identify the sex chromosomes, or using mass spectrometry to locate a sex-specific hormone. More than 15 percent of the layer hens currently alive in Europe (56.4 million hens) have gone through one of these two processes.

Multiple other approaches are in development and have not yet been commercially deployed. Some technologies can “smell” a chick’s sex by analyzing volatile compounds excreted through the eggshell. Another approach uses gene editing so that male eggs have a genetic marker that allows their development to be halted by a simple trigger, such as a blue light. Unlike humans, the sex of a chicken is determined by the chromosomal contribution of its mother. By only modifying the sex chromosome of the female parent line that yields male chicks, the female chicks end up without the gene edit. This means that the eggs they lay do not need to be labeled as “gene-edited” for consumers. While approaches like this may eventually have benefits over the technologies currently used in the market, they are all in the early stages of development.

The beginning of Respeggt's in-ovo sexing circuit. A small hole is made in the eggshell so that a fluid sample can be taken. PCR analysis will determine whether the egg is male or female. Credit: Respeggt—courtesy of Robert Yaman.

In-ovo sexing is rapidly scaling up in the European layer industry. Just last year, the in-ovo sexing capacity on the continent increased by 60 percent, from 17 to 27 installed machines. Initially, adoption was driven by governmental bans on male chick culling in Germany, France, and Italy, but now adoption has expanded to countries without bans, such as Norway, Spain, Belgium, and the Netherlands. In these markets, eggs from hens that were in-ovo sexed sell for a modest 1-3 euro cents more per egg.

In the U.S., economic forces rather than regulation tend to drive the path to market. Earlier this year, the first American egg producer announced their intention to bring in-ovo sexing to the US in 2025. The company, Egg Innovations, is a prominent producer of higher welfare eggs, meaning they already have strong connections to consumers who would be happy to pay a modest price premium for cull-free eggs. Indeed, if the price increase in the U.S. is similar to that in Europe, it will be less than what consumers already pay for other welfare improvements like pasture-raised, free-range, or cage-free eggs.

However, unlike other welfare improvements, in-ovo sexing is fundamentally an automation technology, meaning that the natural incentives of economics and engineering will inevitably push the costs down over time, thereby increasing market share. In-ovo sexing will also unlock other efficiencies for hatcheries such as freeing up incubator space that would have been taken up by male eggs. These factors suggest that in the long term, in-ovo sexing will be cheaper than the current method of paying humans to determine the sex of each chick by hand.

On-Farm Hatching

On-farm hatching is a practice where chicks bypass hatchery processing and transport entirely and instead hatch directly on the farm on which they’ll grow up. On day 18 of the 21-day incubation period, fertilized eggs are almost ready to hatch, so they no longer need to be tilted back and forth by an artificial incubator. They’re removed from the incubator and transported to the farm, still in the protective casing of their shell. At the farm, they are laid out on or near the ground so that chicks can hatch peacefully, without human intervention. Chicks hatched on-farm avoid all of the stress and risk of injury or death associated with hatchery processing and the subsequent live transport.

A newborn chick hatching in an on-farm hatching system developed by Vencomatic. Once the chick is ready to walk, it will gently fall onto the floor of the litterbed with the other chicks. Credit Vencomatic—courtesy of Robert Yaman.

On-farm hatching technology companies provide equipment and infrastructure to make this practice as simple and cheap as possible for farmers. Similar to in-ovo sexing, on-farm hatching is in a “scale-up” phase, with multiple companies actively pushing different solutions onto the market.

One company called NestBorn developed a robot that can drive around the barn and, using vacuum suction cups, remove eggs from hatching trays and place them gently on the litterbed. The machine also has self-disinfecting capabilities to prevent the spread of disease as it travels between many barns. Another company called Vencomatic has a solution where large platforms are suspended from the roof of the barn on which the farmer can directly place hatching egg trays. Once the chicks hatch, they fall a short distance onto the floor of the barn. Between hatches, eggshells can be easily removed, and the suspended platforms can be winched up to the ceiling to allow for cleaning of the barn.

On-farm hatching is currently gaining popularity in Europe for broilers since it has a range of production benefits. Without post-hatch processing and transport, chicks have immediate access to food and water, which allows them to start eating and gaining weight right away. For a broiler producer, this means the chicks start generating economic value more quickly. Immediate access to feed and water also allows for better intestinal development which, combined with the lack of exposure to pathogens during hatching and transportation, significantly decreases the need for antibiotics.

One recent study found that flocks hatched on-farm experienced 44 percent less antibiotic use than conventionally hatched chickens and a 5.6 times greater probability of being antibiotic-free. Another study found that total mortality was around half a percent lower in on-farm hatched chicks. That number may seem negligible, but it would translate to over 46 million chickens spared from premature death each year in the U.S.  

Until recently, on-farm hatching was only possible for broilers, since hatching layers on-farm would mean that males intermix with females. However, in-ovo sexing may enable this technology for layers, allowing egg producers to see many of the same benefits.

For layers, it’s likely that a reduction in early-life stress will have a host of additional benefits for both animal welfare and production efficiency. One study found that less stressed chickens lay more eggs per week and each egg tended to be around 2 grams larger. Early life stress has also been correlated to injurious pecking (referring to hens aggressively pecking at each other on the farm), one of the biggest welfare challenges for egg producers, and the underlying reason for beak trimming at the hatchery. That said, the academic literature surrounding on-farm hatching for layers is still scant, and the long-term effects of on-farm hatching are not yet fully understood.

In-ovo Vaccination

Vaccination is an important part of poultry production to ensure that birds stay healthy and productive. An outbreak of a virus like Marek’s disease can cause tumors and paralysis across an entire flock, which is bad for both animal welfare, and the producer’s bottom line.

All chickens are already vaccinated against common diseases, and the method of vaccination can vary based on the vaccine’s mechanism of action. Some vaccines, such as for infectious bursal disease, are commonly administered through a spray mist, or by squirting a vaccine into each chick’s eye. Other diseases, like Marek’s disease, require subcutaneous injection to be effective. Many of these methods, especially the ones that involve handling, can be extremely aversive for the chick.

In-ovo vaccination, in addition to avoiding this stressful handling, has a number of advantages for the producer. Vaccine administration for eggs is substantially easier than for chicks, meaning that in-ovo vaccinated eggs have a more consistent and uniform delivery across each embryo. Additionally, administering the vaccine pre-hatch gives the chick’s immune system the maximum amount of time to fortify itself against the disease, making vaccination significantly more effective. In-ovo vaccination also allows hatcheries to save on the costs of hiring and training skilled laborers to perform manual post-hatch vaccination.

Fortunately, in-ovo vaccination technology is already fairly advanced, having been common practice in the broiler industry for many years. However, in-ovo vaccination has been uncommon for layer chickens, since the culling of males meant that half of the vaccines go to waste. This is where in-ovo sexing can help, ensuring that only the female eggs are vaccinated.

The Hatcheries of the Future

The emergence of these three technologies around the same time can be explained by taking the perspective of a process engineer. As a unit of engineering, fertilized eggs have a number of advantages over live chicks. Eggs are controllable, immobile, storable, and have a regular shape. There is well-developed automation equipment that can handle huge amounts of eggs in a gentle and orderly way. Eggs can sit snugly and motionless in trays and can be moved with vacuum suction cups for precise handling.

Chicks, on the other hand, are uncontrollable. They move autonomously, need to be fed and watered to survive, and are irregularly shaped. They are sensitive to pathogens in the environment and need to be handled gently to avoid injury or death. Automation equipment for chicks is necessarily cruder—chicks are generally transported down production lines on conveyor belts, either in baskets or simply freely standing on the belts, resulting in unrestrained and chaotic movement. In areas where automation is infeasible, such as the manual sexing of layers, chicks are handled by skilled laborers who are notoriously difficult to hire, train, and retain.

The inherent engineering advantages of fertilized eggs over chicks will be a powerful driver of the adoption of these three technologies across the entire poultry industry. Currently, in-ovo sexing is only used for layers, and on-farm hatching and in-ovo vaccination are primarily used for broilers. However, as in-ovo sexing becomes more widespread, on-farm hatching and in-ovo vaccination may become more common for layers as well.

In the longer term, we may also see in-ovo sexing for broilers. There are already initiatives underway to automate sexing for day-old broiler chicks, given the challenges associated with hiring skilled laborers in today’s economic climate. However, since an individual broiler is less economically valuable than an individual layer, in-ovo sexing would need to be substantially cheaper for broilers than for layers.

Fortunately, in-ovo sexing may also be technically simpler for broilers than for layers, potentially allowing it to attain the required cost point. One of the technical hurdles for in-ovo sexing of layers is that it needs to be done as early as possible in the embryo’s development to guarantee that the embryo will not experience pain when destroyed. The current scientific evidence suggests that at day 13 of the egg’s 21-day development, pain perception cannot be ruled out, meaning that in-ovo sexing for layers should ideally take place before this time. However, during this time window, the embryo is far from fully developed, meaning that many sex-differentiating features may be expensive or even impossible to detect.

However, since broilers are not culled, but rather reared separately by sex, there is little incentive to push in-ovo sexing to work as early as possible. In-ovo sexing of broilers could happen as late as day 18 when eggs are almost ready to hatch because the sex-differentiating features of the embryos will be fully developed. While such initiatives haven’t reached the market yet, it’s possible this will be an application of the technology as costs fall.

Once in-ovo sexing becomes feasible for broilers, it can also unlock sex-specific vaccination. Males and females have slightly different immune systems, meaning that sex-specific vaccination regimes may help keep chickens even healthier. The potential benefits of sex-specific vaccination for vaccines administered in-ovo were previously impractical even to consider, let alone measure. But a combination of in-ovo sexing and vaccination could make this imminently practicable.

With all three of these technologies, the hatcheries of the future will conduct all handling and processing before the chick becomes aware of what’s happening to it, and the first moments of each chick's life will be substantially safer and less stressful. This is by no means the last welfare challenge the chicks will experience over their lives, but the improvements to the first days of life will be immense.

This vision for the future of hatcheries is not far-fetched. The distribution of labor between different parts of the poultry supply chain was determined by those technologies that were available when the poultry industry first industrialized. The artificial incubation of fertilized eggs was one of the first technological revolutions in the poultry industry in the early twentieth century, and the ability to procure and operate these incubators was the driving force behind why hatcheries became a separate part of the supply chain from farms. However, as poultry production technology continues to evolve, the distribution of labor can evolve with it. The logistical challenges associated with handling live animals at the hatchery will be automated away and replaced with more humane in-ovo solutions.

In theory, if there are true economic benefits to this transition, then market pressures should naturally push the industry in this direction without intervention. However, technological changes in industrial sectors always happen slowly, especially in commodity markets like animal agriculture. R&D or new capital expenditure has to fight for a limited pool of cash, especially during crises like COVID supply-chain disruptions or avian influenza.

It follows that, even if the hatchery of the future is a more efficient setup, transitioning will necessarily happen more slowly than it “ought” to if the positive externalities of improving animal welfare are not accounted for. Given the society-wide consensus that improving farm animal welfare is important, we need a broader push to compensate companies for the positive welfare externalities they foster. Business leaders, engineers, and biotechnologists should devote serious effort to improving and scaling the technologies needed to transition to the hatchery of the future, and, in turn, consumers should reward these companies through their purchasing decisions.

Governments also have a role to play. Few government programs exist to improve animal welfare, and the ones that exist usually take the form of command-and-control regulation, solely focused on telling companies only what they cannot do. While such regulations have the right intentions, they do little to alleviate the bottlenecks that businesses face when trying to innovate and improve their practices.

Just as programs like the Inflation Reduction Act have provided massive subsidies for technologies that mitigate climate change, governments should find ways to help companies improve animal welfare, such as through low-interest rate loans or tax credits for animal welfare-improving technologies. In doing so they’ll also be supporting American farmers, and helping to elevate the United States’ position as a moral and technological leader. In-ovo sexing has already had some government support, with the European Investment Bank’s recent loan to the in-ovo sexing company In Ovo and the USDA’s funding of in-ovo sexing R&D.

Farm animal welfare is a cause that receives little attention relative to the amount that people claim to care about it, perhaps because practical, scalable solutions have not yet taken center stage in the discussion. However, technologies like in-ovo sexing, on-farm hatching, and in-ovo vaccination offer the ability to improve animal welfare without sacrificing any of the abundance that industrialized animal agriculture provides. The transformation that these three technologies will bring to the poultry supply chain can serve as a blueprint for how human ingenuity can make our husbandry more efficient, and more humane.


Robert Yaman is the founder and CEO of Innovate Animal Ag, a nonprofit think tank that promotes technology as a practical way to solve the biggest challenges in farm animal welfare. Innovate Animal Ag publishes research on cutting-edge technologies in animal agriculture that could improve animal welfare, then works directly with producers and policymakers to support their development and adoption.

Cite this essay: Robert Yaman. “Before They Hatch.” Asimov Press (2024). DOI:

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