Bone Health: The Next Frontier In Layer Hen Welfare?

At any given time in a year, there are more than 7 billion egg-laying hens kept in the farmed food system globally. Chickens are by far the most populous farmed land animals across the world, and they are generally still raised in extremely poor conditions. Layer hens have been selectively bred in order to maximize their egg production, leading to an immense strain on their health. Without commercial farming, hens would naturally produce around 10-15 eggs per year — but in a factory farm setting, hens have been selectively bred to lay more than 300 eggs in the first year of their lives  – more than twice the average back in 1947. One of the latest goals of the industry is to prolong production cycles beyond the current norm of 72 weeks, with their sights set on getting a total of 500 eggs per hen in 100 weeks.

When discussing the topic of egg-laying hen welfare, cage-free campaigns dominate the public discourse. And while impactful, the egg industry’s ongoing positive transition to cage-free systems still leaves much room for improvement. On the one hand, we are seeing that issues such as feather pecking and poor bone health are prevalent in the industry’s attempts to promote ‘enriched’ cage housing systems, ones where the hens have nest boxes, perches, and scratch pads in the enclosures. Not to mention that despite ongoing campaigns, we still have a long way to go before the majority of U.S. eggs come from higher welfare, cage-free systems, and strategies need to be adjusted to run such corporate outreach campaigns effectively in other regions of the world. The entire ordeal is complicated even further by the fact that simply transitioning towards barn or free-range systems is not enough — the farmers must gain experience and knowledge of the farming practices new to them to ensure high welfare standards for the hens. Birds may still experience higher mortality in the transitional period, despite welfare being superior than in cages, an argument often used by industrial stakeholders expressing a reluctance to change.

Recent controversial COVID-19 relief measures by governments add to the mystery. For example, in an attempt to stabilize rising egg prices, the U.S. FDA chose to aid egg farmers at the cost of biosecurity and animal welfare. Similar risks have been identified in Europe, with the focus set on improving the sustainability of animal farming. It does seem that legislation might be the best and most robust tool to enact impactful welfare improvements and solidify the momentum driven by animal NGOs. Be that as it may, one thing is particularly universal across the different egg farming modes: they all run welfare risks, even the most inconspicuous and least intensive ones, such as keeping backyard chickens.

Issues Abound

The industry has received much critique over the multitude of animal welfare issues associated with egg production. While some are being addressed right now, the efforts seem scattered and are largely region-specific. Issues such as battery cages or beak trimming, for instance, have already been tackled in some places by national bans, while the culling of day-old male chicks seems to be poised to follow the same fate in several countries. However, several other issues are just beginning to reach daylight. They can be broadly grouped into the following categories:

• Environmental: heat stress, inadequate housing design causing injuries or preventing natural behaviors;
• Nutritional: inconsistent quality of feed, its questionable adequacy for the health and welfare of the birds;
• Farming practice related: feather-, toe- and other types of injurious pecking, internal and external parasites;
• Health related: lameness, bone health issues, high mortality at latter production phases.

Although the extent to which any of these issues affect birds in different housing systems and regions varies, right now it seems less of a question as to if welfare issues will affect birds, but a question of how many issues they will face. Higher welfare organic free-range production systems, for instance, still pose many risks for the well-being of birds, thus various welfare metrics need to be monitored closely and continuously across the board.

Particularities Of Poor Bone Health

One group of welfare issues that stick out are the various complications associated with impaired bone development and integrity. An issue prevalent across all systems, poor bone health in layer hens is believed to be behind a major fraction of the total time the birds are forced to spend in pain. None of the improvements in housing systems seem to be significant enough to decrease the incidence of bone fractures in hens — injuries that most birds experience, and which often go unnoticed and barely ever treated. Keel bone (sternum) fractures, in particular, have recently caught the attention of many researchers, so much so that it has become a research subfield of its own. The issue needs immediate attention by experts and animal advocates alike because it affects so many animals and impacts not only their well-being, but also prohibits them from expressing natural behaviors.

A 2020 study on the health of layer hens kept under cage-free housing conditions found that a shocking ninety-seven percent of the birds showed at least one keel bone fracture, while around and above 50% is a common figure published elsewhere. These injuries often go unnoticed as current practices to detect fractures are not accurate or are too costly to be executed on farms, not to mention that there is little incentive for reporting as hens still lay eggs even when injured. When the fractures are not treated, healing can take up to 8 weeks for the majority of hens, with some fractures never fully healing. This suggests that hens experiencing fractures may be in pain and suffering for a significant portion of their lives. Researchers even found that hens suffering from keel bone fractures (KBFs) also experience negative affective states akin to depression, lasting for at least 3 weeks]. There is also evidence suggesting that several issues including poor bone health can combine and multiply the negative effects on hen welfare. Some research, for instance, found a relation between the occurrence of bumblefoot, a debilitating inflammatory disease, and the incidence of KBFs, suggesting that hens with bumblefoot may be more prone to slipping or falling from perches. Likewise, KBF has been found to be linked with poor feather coverage and coordination-related mobility issues.

Unfortunately, there seems to be no easy solution to the problem. With hens now laying 30 times the amount of eggs than they would naturally, there is an enormous strain on their bodies. 

Based on the most recent scientific studies, we are seeing that improvements in farming practices, hen nutrition, and, of course, genetics will most likely all be vital pieces of the puzzle. Be that as it may, one thing is certain — we as advocates must keep raising the issue of poor bone health in layer hens as it is a major source of suffering for so many individuals.

Hen Issues At The Forefront

While research-driven initiatives such as the Welfare Footprint Project and Faunalytics very own Animal Product Impact Scales, are making great strides by uncovering such issues and voicing well-informed concerns, there are also many great animal NGOs taking such information out there and advocating for welfare improvements for the hens. The Open Wing Alliance, for example, is continuously on the lookout for active local groups in an attempt to mobilize and coordinate the cage-free movement in many regions around the world. Besides the obvious welfare improvements that moving away from cages promises, the exercise that the birds can get in these superior housing systems also permits their skeletal systems to get the stimuli they need to develop stronger bones. We also have grassroots organizations like Rettet das Huhn in Germany, working hard to rehome as many farmed hens as possible, providing the birds with loving homes where they are treated as companions and beloved family members for the rest of their lives. We have seen that there still is a need for new organizations focused specifically on hen welfare, and co-founded Healthier Hens. Our goal is to find the most cost-effective way we can help the millions of hens currently stuck in factory farming systems worldwide.

Large-scale change is not out of the question either. Amazing, dedicated advocates are hard at work to make the mistreatment and disregard for chicken needs and sentience a thing of the past. Provieh, for instance, a long-standing animal NGO in Germany, is working towards eliminating keeping egg-laying hens in barns, too – with a goal to have free-range as the standard. They also intend to take on the hen genetics issue by pushing for less intensity in animal farming. International organizations such as the Eurogroup for animals are active on the legislative side of things, informing policymakers how to transition towards more progressive housing systems on the E.U. level. The Scottish Government is also taking a proactive approach, having issued national guidelines with a strong emphasis on laying hen welfare – a welcome step forward.

Hen welfare is finally on the agenda, and we must sustain the momentum and keep demanding a better life for farmed animals, step by step. Most animal advocates should now be able to find an active local NGO working towards improving the lives of farmed chickens, and if not, don’t fret — if anything, the pandemic has taught us how to make the best use of the internet and social media. The hens can use your help in expressing which of their needs are not met and what must be changed, and there has never been a better time to raise your voice.