Are broiler chickens injected with hormones in their left legs?

Question

In my experience, when stores in Bulgaria sell raw chicken legs in packaging, they are always the left leg.

One explanation I have heard is that the left leg is inferior, because it is the site of injections:

Bulgarian news site, Flagman has a 2012 article [Bulgarian].

(Rough translation):

Foreigners are giving us the chicken legs which are injected. Left chicken legs are widely imported in Bulgaria because the well-known fast-growing hormones are injected right into them.

The right legs are reserved for the "rich" western countries, the Telegraph writes.

The foreigners threw away the inflated lefties, but the wasteful practice reached the ears of our businessmen, who immediately arranged regular imports for insignificant sums.

The hormones that chickens are stuffed with in the form of feed mixtures are female. It turns out that the so-called growth hormones, or female hormones, collide en masse in chicken meat. There is currently no product on the market that is not injected with hormones, water and saline solutions.

Thus, in just 40 days, the egg turns into a fatty broiler. Consumption of such meat, however, is not recommended for children and adolescents, as their immune system is incomplete and can not break down hormones. In this way, the boys' bodies are crammed with more female hormones.

I found multiple similar resources that are quoted in many places however I did not find the cited article in Telegraph.

I find this hard to believe; whole chickens are also sold and both legs look the same.

(An unreferenced 2010 answer in Answers.com claims the left leg is tenderer because the chicken scratches with its right leg, but this isn't a notable claim.)

Are either of these theories true? If not, why do we see only left chicken legs in chicken leg packages?

Answer 1

This claim raises so many questions! It is one of funnier claims on the site.

First, does Bulgaria imports chickens? After all, if they grew all their own, this claim wouldn't be true.

Poultry World says yes.

Bulgaria’s poultry imports are dominated by broiler meat, while export revenues come mainly from duck products. [...] Broiler meat imports accounted for 94% of total poultry meat imports and grew over 10% in volume. Frozen broiler meat imports in 2019 increased by 2.2% to 54,000 mt, but its share in total poultry imports was stable at 50%. Frozen chicken leg quarter imports grew 2% over 2018 and remained Bulgaria’s primary imported poultry product.

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Where does Bulgaria get its chickens from?

Poultry World says:

Major suppliers were Poland (40%), Romania (18%) and Hungary (12%).

The USDA mentions Greece as another supplier with an 11% share, but also talks about local production.

Between them, they account for almost all of the broiler chickens sold.

Note in particular, Poland, Romania, Hungary, Greece and Bulgaria are all members of the EU.

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Is poultry in EU countries injected with "well-known fast-growing hormones"?

No! The European Commission has had a ban for decades:

In 1981, with Directive 81/602/EEC, the EU prohibited the use of substances having a hormonal action for growth promotion in farm animals. Examples for these kind of growth promoters are oestradiol 17ß, testosterone, progesterone, zeranol, trenbolone acetate and melengestrol acetate (MGA).

This prohibition applies to Member States and imports from third countries alike. The legal instrument in force is Directive 96/22/EC as amended by Directive 2003/74/EC.

So, the answer to the question is: NO! Chickens do not get injected with growth hormones.

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I took a side trip to find out if chickens had a preferred side (are they "lateralized"?)

Yes! We've only known about this since 1979. It is induced by light during the embryonic stage.

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Given all this, are chickens even asymmetrical?

(Oh man, that feeling when you ask the literature "No-one has even spent serious effort into looking at the lopsidedness of chickens, have they?" and the literature says "Oh, of course they have. I've got your back.")

A 2012 paper investigated the idea that overcrowding chickens might lead to leg deformations, which could be measured by skeletal asymmetries. Such asymmetries ("fluctuating asymmetries" or FA) were assumed to be distributed randomly between the left and right, which allowed them to be compensate for the "directional asymmetries" (or DA) - i.e. when one side was systemically different to the other (which wasn't thought to be due to stress). (So, the authors wanted to known about FA and remove the effect of any DA, but we are only interested in whether DA exists.)

They measured the sizes of toes and lower leg bones (and eyes and beaks etc.) and tried to pick characteristics that didn't have DA.

The DA of the full data set was analyzed as described for the character selection. Although none of the selected characters had shown DA during the character selection, several characters showed DA when all 427 individuals were included. This was likely caused by the increased power of the DA test when performed on this larger sample. Unlike FA, DA is generally not considered an indicator of stress (Klingenberg, 2003) and can lead to biased FA estimates (Van Dongen et al., 1999). Therefore, all measures were corrected for DA by using the unsigned random slopes of the individual regression lines as unbiased estimates of individual absolute FA (Van Dongen et al., 1999).

What does that mean?

It means the paper, unfortunately, didn't describe exactly how asymmetric undeformed, healthy birds are, or in which direction, but yes, chickens are, on average, bigger on one side than the other (and the amount seems to be small.)

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So, why did the OP find that only one side of the chicken is sold in the shops?

I don't have an answer to this.

I am dying to know. I even briefly considered some original research: how much it would cost to "air-task" three or four people to photograph some chicken pieces in their local supermarket, and see if there is even an effect to explain here.

My pet conjecture, that I offer without any evidence at all, is that the OP is right: that this is a widely-believed urban legend in Bulgaria, which has led to a consumer preference for right-handed chicken legs, which leads to them being preferentially selected from the display case by picky shoppers, leaving only the left-handed legs remaining for the OP to find when shopping later in the cycle. Alas, the literature didn't have my back when checking this idea.

Answer 2

Are chickens injected with hormones?

• No, chickens are not given growth hormones.

Please see

Chickens Do Not Receive Growth Hormones: So Why All the Confusion?.

The truth is that no hormones are used in poultry production. Even though the truth speaks for itself, the poultry industry must be vocal if we expect the message to be heard...

The truth is no hormones have been allowed in poultry production for more than 50 years. Hormone use in poultry production was banned in the United States in the 1950s.

And for Europe

Hormones in Meat

In 1981, with Directive 81/602/EEC, the EU prohibited the use of substances having a hormonal action for growth promotion in farm animals.

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Since Bulgaria has been a member state of the EU since 2007, the report from 2012 cannot on the face of it, be true.

However, the question mentions imports and hormones are still used in other parts of the world. This report is dated a year later than the one posted in the question.

Illegal growth hormones roils China's food processing industry

Some poultry farmers in east China's Shandong Province were found to have used excessive amounts of growth-boosting drugs in their chickens, which were then supplied to fast-food giants like KFC, raising further concerns in the country over food safety and the lack of severe penalties for violators.

If the practice is illegal, then the growers won't want it to be easily detected, so they would dump the limbs that were injected. The OP's report says

The foreigners threw away the inflated lefties, but the wasteful practice reached the ears of our businessmen, who immediately arranged regular imports for insignificant sums.

The "insignificant sums" suggests an international black market, and the reason would have nothing to do with the taste.

_{Edit: it is not intended to mean that Bulgarian businessmen bought chicken from this particular company or even from China. It is an example to illustrate that hormones are used even when banned, and growers dump unwanted meat.}