Summary

• Conventional (battery) cages remain legal in the vast majority of countries outside Europe. In particular, in ones in Africa and Asia, which are projected to account for 80.2 % of the global population in 2050. However, I am only aware of impact-focussed organisations advocating for companies to source eggs from cage-free instead of caged hens, not from ones in furnished instead of conventional cages.
• I estimate moving hens from conventional to furnished cages:
  • Increases the welfare of chickens 70.6 % as much as moving hens from conventional cages to cage-free aviaries.
  • Increases the total cost per kg of eggs 24.9 % as much as moving hens from conventional cages to cage-free aviaries.
• So I determine moving hens from conventional to furnished cages increases the welfare of chickens 2.84 (= 0.706/0.249) times as cost-effectively as moving hens from conventional cages to cage-free aviaries from the perspective of the producers.
• I am a bit sceptical that advocating for furnished cages increases the welfare of chickens more cost-effectively than for cage-free aviaries. I understand many people have an intuition that cage-free hens have higher welfare than caged hens. In contrast, the difference between conventional and furnished cages is not obvious. I would still try advocating for furnished cages despite this. It does not directly present a downside, and does not seem like an insurmountable challenge.
• My main concern about advocating for furnished cages is decreasing the cohesiveness of global efforts targeting laying hens. On the other hand, furnished cages are an easier ask, and therefore may lead to more welfare reforms, thus creating momentum for the global efforts towards cage-free. I overall lean towards flexibility.

Context

The countries with active national bans on keeping hens in conventional cages are in blue below. They mostly are all the countries in the European Union (EU), where conventional cages have been banned since 2012, and a few more in Europe, including Norway, Switzerland, the United Kingdom (UK). French Guiana, a department of France, is the blue area in South America, and Bhutan is the one in South Asia. Canada and New Zealand, in yellow below, have passed bans. Australia, India, and the United States, in purple below, have active subnational bans. Yet, conventional cages remain legal in the vast majority of countries outside Europe. In particular, in ones in Africa and Asia, which are projected to account for 80.2 % (= (5.28 + 2.47)/9.66) of the global population in 2050. However, I am only aware of impact-focussed organisations advocating for companies to source eggs from cage-free instead of caged hens, not from ones in furnished instead of conventional cages.

Welfare

I estimate that hens in conventional (battery) and furnished (enriched) cages, and cage-free aviaries (barns) have a welfare of -1.79, -1.09, and -0.798 chicken-QALY/chicken-year. Fully healthy hens would have a welfare of 1 chicken-QALY/chicken-year. The lives of hens with a welfare of -1 chicken-QALY/chicken-year are as further away from being neutral as those of fully healthy hens, but are negative (more suffering than happiness) instead of positive (more happiness than suffering). Based on my estimates, moving hens from conventional to furnished cages increases the welfare of chickens 70.6 % (= (-1.09 - (-1.79))/(-0.798 - (-1.79))) as much as moving hens from conventional cages to cage-free aviaries. So I believe furnished cages are better than midway between conventional cages and cage-free aviaries.

I got the welfare for different conditions using underestimates from the Welfare Footprint Institute (WFI) for the time chickens spend in annoying, hurtful, disabling, and excruciating pain, which is illustrated below. I obtained best guesses for the time in pain adjusting WFI’s underestimates based on comments from Cynthia Schuck. I aggregated all the information about the time in pain with my guesses for the intensities of the 4 categories of pain. I accounted for positive experiences.

I value increasing happiness, and decreasing suffering proportionally to their probability, duration, and intensity. In other words, I only care about increasing expected total hedonistic welfare. In this case, my best guess is that moving hens from conventional to furnished cages is 70.6 % as beneficial as moving hens from conventional cages to cage-free aviaries. However, I think the fraction would be even higher if decreasing more intense suffering had a special value (higher than proportional to its intensity). The time hens in conventional and furnished cages spend in disabling/excruciating pain is very similar according to WFI’s underestimates, as illustrated above and below. My best guesses are still similar, but less similar because Cynthia noted accounting for the neglected welfare issues would increase the time in pain in the baseline conditions more than in the improved conditions. I got 213 and 195 h of disabling pain for hens in conventional and furnished cages.

Cost

Below is the cost of egg production in Northwest Europe by housing system according to Table 1.1 of van Horne and Bondt (2023). The increase in the total cost per kg of eggs from conventional to furnished cages is 24.9 % (= 0.0526/0.211) of that from conventional cages to cage-free aviaries. In contrast, I determined above it would capture 70.6 % of the benefits.

Cost-effectiveness

From my numbers above, I determine moving hens from conventional to furnished cages increases the welfare of chickens 2.84 (= 0.706/0.249) times as cost-effectively as moving hens from conventional cages to cage-free aviaries from the perspective of the producers. So I conclude it is worth considering advocating for furnished cages instead of cage-free aviaries, especially in countries like China where advocating for cage-free aviaries has had little success.

Discussion

I am a bit sceptical that advocating for furnished cages increases the welfare of chickens more cost-effectively than for cage-free aviaries. I model companies as interested in maximising profit as a 1st approximation, and this crucially depends on consumers’ choices. I understand many people have an intuition that cage-free hens have higher welfare than caged hens. One can easily visualise the difference between caged and cage-free hens, and only the latter is compatible with an idyllic view of the conditions of farmed animals. In contrast, the difference between conventional and furnished cages is not obvious. I would still try advocating for furnished cages despite this. It does not directly present a downside, and does not seem like an insurmountable challenge. Hens in furnished cages in the EU are required to have “at least 1 nest for every 7 hens”, “adequate perches (at least 15 cm per hen)”, and “at least 250 cm2 of littered area per hen”. I assume there are ways of communicating to the public these elements are important. Even if not, there may still be room to advocate for political change in more authoritarian countries like China where companies are less subject to public pressure.

My main concern about advocating for furnished cages is decreasing the cohesiveness of global efforts targeting laying hens. On the other hand, furnished cages are an easier ask, and therefore may lead to more welfare reforms, thus creating momentum for the global efforts towards cage-free. I overall lean towards flexibility. Likewise in the context of increasing the welfare of broilers, where I believe it often makes sense to argue for slow growth breeds or lower stocking density individually instead of all the elements of the European Chicken Commitment (ECC) together.

Some may argue against advocating for replacing conventional with furnished cages due to the increase in welfare being too small. However, I estimate going from conventional to furnished cages increases the welfare of chickens 2.40 (= 0.706/(1 - 0.706)) times as much as going from furnished cages to cage-free aviaries, and many people are on board with advocating for this.