Welcome to the Ethical Guide reboot! Hopefully I’ve learned some things in the decade since I last did this (the Daily Footprint posts) but in any case I didn’t cover eggs before. I don’t review many animal products on the GSP, but I’m often going on about their social and environmental impact because a lot of roads lead there. But rather than just saying, everyone must go vegan, it’s important to look at the relative impacts of our food choices.

Let’s do a brief recap of key images, focusing in on eggs. We’ve examined various social and environmental impacts of food here on the GSP that led to an ethical ranking of our protein sources.

I’ll briefly highlight a couple of the environmental impacts (based on this seminal paper by Poore and Nemecek) behind this ranking – carbon footprint and land footprint. Observe where eggs lie on the chart below, which ranks the carbon footprint of various protein sources – just above tofu but well below all the animal products

As it turns out, the carbon footprint of products from ruminants (beef, lamb, and cheese) are even higher than the numbers shown in the chart above when we factor in land use. See my post on a revised carbon footprint for beef (estimated at 227 kg CO₂eq / kg) for more detail on that. On the amount of land it takes to produce 1 kg of beef – we can produce 52 kg of eggs – that’s one thousand eggs, a three-year supply.

Environmental footprints: eggs vs. cheese

Finally it’s useful to compare the environmental footprints of eggs versus cheese – this was a big one for me, as a vegetarian, to know that one is far better than the other. The chart below compares cheese and eggs across five major environmental footprints – you can see that cheese has a much larger footprint in each case.

Data like this suggests that eggs are among the best animal products – perhaps only rivaled by certain kinds of seafood (and insects, maybe). Cutting red meat should be the primary goal of an ethical diet, and then choosing eggs over cheese has a big impact too.

Thanks for bearing with me on that recap. The remainder of this post will focus on a recent improvement in animal welfare for Gallus gallus domesticus (aka the chicken), the world’s most numerous bird species. It’s called in-ovo sexing.

A major ethical issue with eggs and dairy

How to put this: dairy and eggs both spell bad news for boys. Both of these industries rely on females – dairy cows and laying hens – and there’s not so much demand for the males.

Dairy: Cows bred for milk production are different to the breeds raised for beef and males born to dairy cows are less desirable, as a result. In certain locations (in the UK, for example) some calves are killed within days of birth due to lack of demand for veal/beef from dairy breeds. This situation is generally improving, thanks to increased awareness and approaches such as sexed semen (which reduces male births), but ethical issues in dairy remain.

Eggs: At hatcheries that provide laying hen breeds to farmers, males are usually killed right after hatching and gender identification by an employee. That’s how it has been for years – around half of the chicks hatched are male and (being a different breed to chickens raised for meat) they are killed at birth – about 7 billion chicks per year. However, recent scientific and technical advances allow gender identification of chicks about a week into their 3-week incubation period.

In-ovo sexing

There are several different technologies in contention for sexing (gender identification) of chicks during egg incubation. The first successful application of in-ovo sexing used an approach developed at Leipzig University in Germany.

They found that by day 9 of development, female embryos produce a hormone called estrone sulfate that can be detected reliably in fluid that builds up in the egg. The company built a robot that fires a laser to open a hole in the shell much smaller than a pinhead. It sucks out a minuscule drop of the fluid and adds it to a solution that turns blue in the presence of the female hormone. – Science (2019).

A company, Seleggt, was developed from this university work in 2017 (a collaboration between HatchTech and retail group REWE) and the first product was launched in Berlin REWE supermarkets at the end of 2018. Cartons of eggs were labeled with the message “Ohne Kükentöten,” which translates to without chick culling.

Pushback against in-ovo sexing

In 2020, Vital Farms, the largest producer of pasture-raised eggs in the US had its IPO. I contacted the company, knowing that in-ovo sexing was on the company’s agenda but I received a response suggesting that the technology wasn’t yet sufficient for their needs:

Unfortunately, there haven’t been any major breakthroughs yet and all hatcheries in the US still cull male chicks. Though we don’t own or work directly with our hatcheries, we’ll continue to advocate for the progression of new technologies that could eliminate this terrible practice.

Clearly the technology was been applied at a commercial scale in Germany, but I guess it wasn’t ready for primetime in the US. I presumed that this was a matter of scale or economics but there may have been other issues at play.

By 2022 it emerged that UK supermarkets didn’t want to stock eggs with labels promoting messages such as “without chick culling.” They also didn’t want the UK to follow in the footsteps of Germany and France to ban chick culling:

Germany brought in legislation to outlaw the killing of day-old male chicks at the start of 2022, while French poultry farmers have until the end of this year to comply with a new law banning the practice. The UK has no such legislation. – The Guardian.

What was the reason for this reaction in the UK? Optics, for the most part. Carmen Uphoff, Respeggt’s chief operating officer, commented on barriers to entering the UK market:

I have suggested starting with just one brand that is ‘free of chick culling’ on the shelves but, again, the response is that the customer will realise all the other eggs are ‘with chick culling’, and they wouldn’t have known that before.

Well that says it all, really. It also underscores the importance of supporting ethical retailers – a topic for a future post.

2025: in-ovo sexing gets a start in the US

I guess this blog post was six years in the making, but finally some good news has hit US shores.

In 2025 the American market began to adopt in-ovo sexing. With NestFresh bringing the first in-ovo sexed eggs to American shelves and several other major egg producers announcing their intentions to adopt in-ovo sexing, interest in in-ovo sexing appeared to be accelerating as the year came to a close. – Innovative Animal Ag

How to find eggs from humanly hatched hens

In-ovo sexing has become common practice in mainland Europe (but not the UK*) – it looks like over a quarter of the eggs sold in the EU are now from hens hatched using in-ovo sexing technology. There a few different labels to indicate hens were humanely hatched, including the German Ohne Kükentöten (OKT) label, mentioned above, and a similar certification in the Netherlands, called ZED.

*In the UK, there’s one poultry breeder (Piggotts) that supplies in-ovo sexed chicks mainly to hobby and small-scale egg farmers. Last year, the Vegetarian Society launched a campaign in the UK urging the government to ban male chick culling and support ethical breeding.

In the US, the main logos to look out for are the Certified Humane Approved Hatchery certification and also Hatch Check (both pictured earlier). I’ve been on the lookout for them in my local supermarkets and did come across eggs from early adopter Nest Fresh (pictured below) in Whole Foods. Apparently, Kipster will start labeling their better-hatched eggs with the Certified Humane® Approved Hatchery logo on egg cartons in late 2026, when all of its eggs are compliant.

In summer 2025, a Brazilian company became the first in the Southern Hemisphere to adopt in-ovo sexing, using a technology that was works differently to the Respeggt method.

Health impacts of eggs

To wrap this up I want to briefly mention this useful commentary on the health impact of including eggs in our diet. There are many papers claiming that eggs are bad for health but also many papers claiming that eggs are good for health. The reason for this discrepancy is that it depends on what you’re comparing eggs to!

The table below shows that eggs eaten instead of plants may increase cardiovascular disease (CVD) and cancer risk. However, eggs eaten instead of an equivalent amount of cholesterol-rich meat and dairy will actually reduce CVD and cancer risk (Experiment 3 in the table).

In other words, eggs are not as healthy as veggies but are healthier than meat and dairy.

Thus, we can improve this interpretation for eggs and mortality as a substitution for butter, milk, sausage, and other foods. When the model explicitly contrasted eggs against higher amounts of dairy, processed meats, and other high-cholesterol foods, men eating more eggs and fewer of these other products actually had a lower risk of death.” – Deirdre K Tobias, Brigham and Women’s Hospital and Harvard Medical School.

If you’d like perspective on the health impact of cheese, I recommend checking out The Cheese Trap, by Dr. Neal Barnard. I’m not a huge fan of books on dietary advice from MDs but this one is full of useful information that will likely make you rethink cheese.

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Thanks for sticking with me through this long piece. Personally, I still support vegan egg substitutes such as products made by Just, or homemade vegan scrambled eggs. But, as someone who still occasionally eats dairy and eggs, I now believe that eggs are a much better choice than dairy (and are way better than beef!).