Dossier Ventilation Shutdown: How to Kill Half a Million Chickens at Once

Published on February 9, 2016 on Motherboard.vice.com, Written by Kaleigh Rogers. You’d be hard pressed to find someone who would argue that killing a flock of chickens by shutting down ventilation systems to their barn and letting them slowly overheat and suffocate is a pleasant way to go. In fact, a year ago, this method of killing sick birds—called ventilation shutdown—was not permitted by the Department of Agriculture. But after a devastating bout of highly pathogenic avian influenza (HPAI) decimated US chicken and turkey farms last year, the USDA approved and has started using this controversial killing technique to cull infected flocks at massive, commercial farms in an effort to prevent another outbreak.

Nobody is keen on killing hundreds of thousands of chickens at a time—aside from it being a grim task, it also results in a huge loss of revenue—but it’s a necessary evil to shut down disastrous outbreaks. The USDA acknowledges that ventilation shutdown is not a great way to go, though a representative told me the agency can’t say for sure how long it takes birds to die this way. The fact that the USDA would resort to a killing technique most experts agree is less-than-ideal at best and inhumane at worst, without fully understanding what this method does to the animals, shows how ill-prepared we are for dealing with a massive agricultural epidemic. If we want to be more prepared in the future, shouldn’t the USDA be looking for better ways to kill half a million birds at once?

When a flock of poultry is infected with HPAI, swift action is imperative. As long as the birds are alive, they actively shed the live virus through their feces and saliva, which increases the risk of the disease spreading to other farms. So when the virus is detected, the USDA requires the flock to be depopulated—a term meaning the mass killing of livestock in response to a disease outbreak—within 24 hours. In some cases, like on some turkey farms in Indiana last month, this means resorting to ventilation shutdown.

“I don’t think anyone denies that there are more welfare challenges with ventilation shutdown than any of the other techniques,” said Maurice Pitesky, a veterinarian and expert in poultry epidemiology at the University of California. “But if you’re just thinking solely about how to depopulate the flock, ventilation shutdown is the quickest way to do that.”

It’s true that, from a procedural standpoint, ventilation shutdown is the option that can be executed most quickly. Other methods, like gassing the birds with carbon dioxide or suffocating them with a dense CO2 foam, require more time to orchestrate: you have to find a way to get a CO2 tanker to the farm, pump the gas into the barn, and wait for the concentration to get high enough to depopulate the flock. Depending on the location and size of the farm, this could take more than 24 hours to complete—beyond the USDA’s deadline. Ventilation shutdown, on the other hand, is just a matter of flipping a few switches.

The USDA guidelines for ventilation shutdown are to turn off the ventilation systems, then raise the temperature inside the barn to at least 104F for a minimum of three hours. This can be done by turning up the temperature, but because the barns are so densely packed they can sometimes heat up that much just by virtue of the air systems being shut off. It’s happened in the past by accident, when pranksters shut off power or electrical failures cause the air systems to shut down. From start to finish, the actual process is the quickest way to depopulate a flock.

The trouble is that, for each individual bird, it might be one of the slowest and most painful ways to die. Paul Shapiro, vice president of farm animal protection for the Humane Society of the United States, described the process as “essentially baking the birds to death,” and called it “horrific.”

The HSUS claims it could take birds hours to die through ventilation shutdown, but there are no studies that have looked at the time to death with this method. USDA officials have previously estimated the process takes 30 to 40 minutes to kill birds, but when I reached out to the agency, it couldn’t confirm how long it takes birds to die this way.

“The majority of birds will die quickly, but it is advisable to maintain the recommended temperature for three hours to account for poor heat distribution and, importantly, inactivate much of the HPAI virus in the poultry house,” Andrea McNally, a spokesperson for the USDA Animal and Plant Health Inspection Service, told me, stressing that ventilation shutdown was considered a last resort option. When I asked McNally to clarify what the USDA considered “quickly,” she said she couldn’t.

“The variabilities of structures and density of poultry make it hard to give you an easy answer,” McNally said.

It’s not all that surprising that the USDA doesn’t know precisely how long it takes birds to die via ventilation shutdown, because nobody really does, according to Patricia Turner, a veterinarian and pathobiology professor at the University of Guelph who has researched depopulation methods and is a consultant on the American Veterinary Medical Association’s depopulation panel.

“It hasn’t been studied, to be very honest,” Turner told me over the phone. “You want the animal to become insensible as soon as possible. The time to death is pretty rapid with ventilation shutdown, within probably 10-25 minutes depending on the size of the barn. The problem is that we don’t know what the animals experience in that time.”

One of the arguments in favor of using ventilation shutdown is that if farmers delay in an attempt to use another method like CO2, the virus could spread, putting even more animals on death row. But if there are other, potentially more humane methods, why aren’t we set up to put them in place quickly if needed?

“It’s unheard of, the methods they’re applying,” said Harm Kiezebrink, an expert in humane poultry depopulation who has developed painless slaughtering technology. “Anybody with a little common sense understands that if you don’t research animal welfare for a method that is now the standard, that is very, very bad.”

Kiezebrink has worked around the world to help governments manage avian influenza outbreaks, depopulating farms from the Netherlands to China. Ventilation shutdown isn’t widely used in other countries, according to Kiezebrink (gassing is usually preferred). It was green-lit in the UK in 2006 but never implemented. It’s far from the most gruesome depopulation method around—in the past, some countries have resorted to burning or burying birds alive—but Kiezebrink said the lack of understanding of the method’s effect on birds should rule it out, at least until further research is done.

But other options aren’t cheap. The technology Kiezebrink once marketed—including a machine that kills birds instantly by dragging them through electrified water—cost as much as $600,000. Recently Kiezebrink said he’s been researching a nitrogen-based foam that would, he says, basically just put the birds to sleep when inhaled. But this, too, would likely be too expensive to use on a widespread basis.

“Gas-injected foam is better because the animals actually die of lack of oxygen, which occurs much faster and much more quietly—they don’t seem to show the same distress,” Turner told me. “The problem is nitrogen is expensive and difficult to source. For the huge farms prevalent in the US, which are much bigger than anything in Europe, it’s probably not feasible.”

So where does that leave us? The good news is, after the ventilation shutdown in Indiana, there haven’t been any more reports of HPAI so far this year. That buys us some time to work on more humane methods, including potentially developing vaccines, Turner said. She said when the AVMA completes its depopulation guidelines, the USDA will likely need to reassess its use of ventilation shutdown.

“I would be very surprised to see this technique accepted [by the AVMA] without peer-reviewed papers that support it,” Turner said. “In addition to needing data on it, there needs to be public acceptance. You can think of a number of procedures that might be very quick but would not be interpreted to be humane, or that the public just might not have the stomach for.”

Dossier culling methods: Practical experiences in the culling of poultry in Germany

This presentation is based on the practical experiences in culling poultry in Germany, gives an overview of the culling techniques currently in use in Germany. It is presented by dr. Ursula Gerdes, dr. Josef Diekmann and ing. Rainer Thomes. Together, they form the expert team on eradication of animal diseases, working for LAVES.

LAVES is the Lower Saxony State Office for Consumer Protection and Food Safety, located in Oldenburg, Germany. With around 900 employees they are entrusted with tasks in the areas of food and utensil inspection, feed inspection, meat hygiene, veterinary drug monitoring, eradication of animal diseases, disposal of animal by-products, animal welfare, ecological farming, market surveillance and technical process monitoring.

Dossier H7N8: Frigid Air Slows Efforts to Euthanize Turkeys in Indiana

ABC news online, Jan 18, 2016. Frigid temperatures are hampering efforts to euthanize turkeys at several southwestern Indiana farms where a strain of bird flu was found last week, freezing the hoses used to spread a foam that suffocates the affected flocks, a spokeswoman for a state agency said Monday.

The H7N8 virus was discovered on 10 turkey farms in Dubois County, which is Indiana’s top poultry-producing county, last week.

Temperatures that dipped into the teens and single digits over the weekend stymied efforts to fill the affected poultry barns with the foam to a level just above the turkeys’ heads to suffocate them, said Denise Derrer of the Indiana State Board of Animal Health.
“The water’s been freezing up. It’s slowing things down, but we’re doing the best we can,” she said.

Derrer said state workers, staff from the U.S. Department of Agriculture and others have been using carbon dioxide gas instead of the foam. Other turkeys are being killed manually with a device that delivers a fatal head injury, but that method is slow and inefficient, she said.

While the USDA has a goal of euthanizing infected poultry within 24 hours of the discovery of infected flocks, it’s not a requirement, Derrer said, adding that workers are trying to euthanize flocks as quickly as possible.

As of Monday, nearly 120,000 turkeys had been killed on four of the farms, while efforts to euthanize about 121,000 turkeys continued on six other farms.

The H7N8 strain is different than the H5N2 virus that led to the deaths of 48 million birds last summer, mostly in the upper Midwest.

The first farm where H7N8 was found had a highly contagious form of the virus, Derrer said, but tests by USDA staff have shown eight of the other nine turkey farms have a “low pathogenic” form, meaning the birds are more likely to get sick but not die.

The results also suggest that the outbreaks were caught earlier in the disease cycle before the virus had a chance to mutate and become more virulent.

Test results on viral samples taken from the ninth farm are still pending. All of the affected farms were within six miles of the first one; officials are still monitoring other farms and backyard flocks within that distance, Derrer said.

Dossier H7N8: All flocks in Indiana ‘euthanized’?

WattAgNet.com, January 21, 2016. Depopulation has been completed at 10 turkey farms with confirmed avian influenza detections and another nearby layer farm deemed at risk. Depopulation procedures have been completed at 11 farms in Dubois County, Indiana, after the presence of H7N8 avian influenza had been detected at 10 of those farms.

According to the Indiana State Board of Animal Health, 413,163 birds have been depopulated since avian influenza was first confirmed in Dubois County on January 15. Of the birds euthanized, 257,163 were turkeys and 156,000 were layer chickens.

Ten of those farms were commercial turkey operations, while the layer operation was not infected with avian influenza. However, the Dubois County layer flock was depopulated as a precaution because of its “dangerous” proximity to the affected flocks.

The first and largest turkey flock to be affected was confirmed to have been infected with highly pathogenic H7N8 avian influenza, while nine others were confirmed to have been hit by a low pathogenic strain of H7N8. The other turkey flock tested positive for the presence of H7N8 avian influenza, but it has not yet been determined whether it was a highly pathogenic or low pathogenic strain.

The flock hit by highly pathogenic avian influenza included 62,213 turkeys.
The bird carcasses from those farms are being composted in the buildings in which they were euthanized.

The Indiana agency reported that during a 24-hour period that started on January 19, 114 commercial farms tested negative for avian influenza. Of those, 62 farms were in the initial 10-kilometer control zone, while the others were in an expanded zone that covered an additional 10 kilometers. The expanded zone includes not only Dubois County, but also Crawford, Daviess, Martin and Orange counties.

State and federal teams have visited nearly 1,600 residences near the site where the first confirmed avian influenza case occurred to search for backyard flocks for precautionary testing. The teams found 67 backyard flocks within that area, and those birds are being tested.

Dossier H7N8: Indiana avian flu cases test ventilation shutdown protocol

WattAgNet Online, 19 January 2016. Emergency depopulation method approved by USDA in September 2015 has been successfully initiated.

Depopulation of birds affected by H7N8 avian influenza by ventilation shutdown has been successfully implemented for the first time.

Within the past week, 10 Indiana turkey flocks have been affected by H7N8 avian influenza. Of those ten flocks, one was classified as highly pathogenic while eight others were of the low pathogenic strain. Tests conducted on the tenth flock have not yet determined whether the birds were affected by a highly pathogenic or low pathogenic strain.

According to information provided by the National Turkey Federation, six of the ten affected flocks were successfully depopulated by January 18, while depopulation efforts were underway in the other four. Ventilation shutdown was effectively utilized, according to NTF. In addition, depopulation by foaming was also done, but below freezing temperatures caused operational difficulties with foaming machines.

Ventilation shutdown was approved by the USDA in September as an emergency method to depopulate poultry flocks that have been affected by avian influenza. The agency approved the conditional use of ventilation shutdown because traditional depopulation methods did not always kill affected birds quickly enough to control the spread of the virus as effectively as desired. However, since the last time a U.S. flock had been infected with avian influenza was in June 2015, veterinary officials had not yet had the opportunity to implement ventilation shutdown until the Indiana flocks were infected.

Dossier Stable Gassing: Scientific review on killing spent laying hens on the farm

September 2015: In Sweden, spent laying hens are killed either by traditional slaughter; on-farm with CO2 in a mobile container combined with a grinder; or with CO2 stable gassing inside the barn. The number of hens killed using the latter method has increased. During these killings a veterinarian is required to be present and report to the Swedish Board of Agriculture.

Data were registered during four commercial killings and extracted from all official veterinary reports at CO2 whole-house killings in 2008–2010. On-farm monitoring showed that temperature decreased greatly and with high variability.

The time until birds became unconscious after coming into contact with the gas, based on time until loss of balance, was 3–5 min.

Veterinary reports show that 1.5 million laying hens were killed, in 150 separate instances. The most common non-compliance with legislation was failure to notify the regional animal welfare authorities prior to the killings. Six out of 150 killings were defined as animal welfare failures, eg delivery of insufficient CO2 or failure to seal buildings to achieve adequate gas concentration. Eleven were either potentially or completely unacceptable from the perspective of animal welfare.

This study shows that there are grounds for concern regarding the latter. However, there remain several risks to animal welfare and increased knowledge would appear vital in order to limit mistakes related to miscalculations of house volume, improper sealing or premature ventilation turn-off.

There are aspects of animal welfare that should be taken into account: concerning the use of CO2 in the barn to euthanize spent method of killing itself, which have been studied extensively (e.g. Sandilands et al 2011; McKeegan et al 2012; Turner et al 2012); besides, the hazard to welfare when the method is performed on a larger scale, commercially, and the legislation or standard operating procedures for the euthanasia are not adhered to.

Dossier H7N8: USDA APHIS confirmed outbreak on commercial turkey farm in Dubois county, Indiana

Bloomberg Business online, January 15, 2016. The U.S. Department of Agriculture said it confirmed the diagnosis on January 11, 2016, the presence of a highly pathogenic strain of avian influenza in a commercial turkey flock in Indiana, the country’s first case since the end of last year’s outbreak that led to the destruction of 50 million animals.

The H7N8 strain discovered at a 60,000-bird flock in Dubois County is different from those that caused last year’s outbreak, the U.S. Department of Agriculture’s Animal & Plant Health Inspection Service said Friday in a statement on its website. Federal and state authorities are monitoring and testing the nearby area, it said, without naming the exact site.

The USDA contacted countries that buy poultry and eggs after the detection and hasn’t received any notice of official import restrictions, T.J. Myers, associate deputy administrator at the inspection service’s APHIS, said on a conference call with the media. The USDA is working to “minimize the trade impact,” Myers said.

U.S. poultry producers have been on edge after recent cases in France. The 2015 U.S. outbreak, which ended in June, led to record-high egg prices and caused some shortages of turkey deli meat used in subs and sandwiches. It cost the industry $3.3 billion.
Rapid Response

Producers have been discussing the new outbreak in a series of conference calls since they first became aware of the Indiana case late Thursday, said John Brunnquell, president of Egg Innovations LLC, which produces free-range eggs in farms across the Midwest. The response has been rapid, with the killing of birds going on throughout the night, he said in an interview.

“The timing of the disease was a surprise because most in the industry did not think it would reappear for another two or three months,” said Terry Reilly, a senior commodity analyst for Futures International LLC in Chicago.

Preliminary tests indicate the H7N8 strain found in Indiana was of North American origin, according to the USDA’s Myers. The USDA will conduct diagnostics to seek a cause for the mutation of the virus, he said.
Different Strain

Determined to avoid a repeat of the nation’s worst-ever avian-influenza outbreak, the USDA stockpiled millions of doses of a new vaccine designed to fight the 2015 strain, which is different than the one in Indiana, Myers said.

“Concerns are huge, but we cannot pull the panic button until we know quite a bit more,” said Bill Lapp, the president of Advanced Economic Solutions in Omaha, Nebraska. “Because it is found in a different state, and is a different strain, it makes an even greater mystery.”

Sixty-five egg and turkey farms are within 10 kilometers (6.2 miles) of the affected barn, said Brunnquell of Egg Innovations. The area is home to an estimated 4.5 million egg-layers and about 1 million to 2 million turkeys.

Producers within 10 kilometers of the affected barn can’t move products or animals without testing to determine if they are free of the virus, Denise Derrer, a spokeswoman for the Indiana Board of Animal Health, said in a telephone interview.
Testing Birds

The affected producer began terminating birds in nine other barns on the farm after tests showed the virus was highly pathogenic. A bird flu test conducted by a Purdue, Indiana, laboratory came back positive yesterday, Derrer said.

No other signs of the virus have yet been detected, she said. Government teams will travel to the area to contact people raising backyard flocks on Saturday to test more birds.

Indiana’s poultry industry ranks fourth nationally in turkey production, first in duck production and third in eggs. It also is a significant producer of broiler chickens.

Shares of poultry producer Pilgrim’s Pride Corp. closed 5.2 percent lower in New York, the most in three months. Tyson Foods Inc., which produces chicken and other meats, fell as much as 5.5 percent before closing down 2.7 percent.

The case of avian flu in Indiana doesn’t involve Tyson, Hormel Foods Corp., Cargill Inc., Maxwell Farms LLC’s Butterball or Sanderson Farms Inc., according to company e-mailed responses.

The news of the case of bird flu was a boost for Cal-Maine Foods Inc., the largest U.S. egg supplier. Its stock jumped as much as 11 percent before closing up 5.2 percent.

Avian influenza doesn’t present a food safety risk. All shipments of poultry and eggs are tested to ensure the absence of avian influenza before moving into the food supply. The Centers for Disease Control considers the risk of illness to humans to be very low.

Dossier egg production: Mexico’s Grupo Bimbo changing to cage-free eggs

WattAgNet.com. December 2015: Mexican company expects to complete transition globally by 2025. Grupo Bimbo, a leading Mexican and global baking company, and owner of brands like Bimbo, Marinela and Tía Rosa, committed to eliminating battery cages from its liquid and shell egg supply chain and only purchasing cage-free eggs in Mexico and globally. Grupo Bimbo will complete this transition to cage-free eggs in Mexico and globally by 2025.

Rosalío Rodríguez, global senior vice president of operations, Grupo Bimbo announced that the company’s efforts to carry out this transition in favor of animal welfare, adding that “With this commitment, Grupo Bimbo honors its Social Responsibility Model and we believe this action will become a common practice in the future.”

Grupo Bimbo joins dozens of companies that have already committed to eliminating battery cage eggs from their supply chains, including Unilever, Nestlé, General Mills and Starbucks.

Grupo Bimbo has a presence in Mexico, United States, Canada, Latin America, China and the UK.

Humane Society International (HSI), one of the world’s largest animal protection organizations, welcomed Grupo Bimbo’s announcement.

Elissa Lane, deputy director of HSI Farm Animals, said: “Consumers care about the way animals are treated in food production and we are glad to see Bimbo taking these concerns seriously by committing to shifting to a 100 percent cage-free egg supply chain.

Bimbo’s egg policy will improve the lives of countless animals and sends a clear message to the egg industry in Mexico and around the globe that cage-free production systems are the way forward.”

Dossier Piglets: German TV Report creats pressure regarding killing piglets on farms

Killing piglets on the farm remains a hot issue in Europe, demanding new methods. On January 12, 2016, the program of ARD Report (German National TV) broadcasted second program on the current method of killing piglets on the farm.

This program was the follow-up of the first Report program, published in June 2015, showing the embarrassed German Agricultural Minister. He explained that after the first Report program, the German politic forced the responsible German veterinary authorities to develop new techniques to introduce new methods that prevent unnecessary stress or pain during the stunning and killing , but according to this new footage, nothing has changed: the animals are still stunned by brute force and there is no control if the piglets are stunned before their throats are cut.

To change this situation, a team of specialists of the Friedrich Loeffler Institute in Celle/Germany, AVT Applied Veterinary Technologies – Innovation & Services (Germany) and Anoxia Europe (Holland) are working on legalizing the Anoxia method for this purpose.

Dossier USA: US cage-free egg layer flock is rapidly increasing

WhattAgNet.com, Terrence O’Keefe, November 16, 2015. Poultry housing expansion projects are being shifted to cage-free as the number of restaurant chains making cage-free egg purchasing pledges continues to grow.

The U.S. Department of Agriculture (USDA) estimates that, in September 2015, the U.S. had 23.6 million hens housed cage free, a 37 percent increase from the agency’s September 2014 estimate. Pledges to purchase eggs from cage-free layers by major restaurant chains and food companies are driving this increase.

Industry sources expect the U.S. cage-free layer flock to continue to grow at a rapid rate. Among the many projects underway, the three largest egg producers in the U.S. are designing and building cage-free farms that will become the largest cage-free egg facilities in North America.

Cage-free laying flock increasing

USDA estimates for the size of the cage-free layer flock in the U.S., for organic and non-organic egg production, are published on a semi-annual basis (see Figure 1). From March 2013 through March 2015, the size of organic and non-organic cage-free layer flocks were roughly equal, with both increasing by a little over 1 million hens in this two-year period.

The sale of other (non-organic) eggs is expected to increase more rapidly than organic eggs sales during the next few years.
Between March and September 2015, the rate of growth of the organic and non-organic layer flocks increased. The size of the U.S. organic layer flock increased by 19 percent in this six-month period, while at the same time the non-organic or “other cage-free” layer flocks increased by 27 percent.

Egg producers announce expansion

Several announcements of new farm projects for housing cage-free laying hens by major U.S. egg producers have been made in the past year. Hickman Family Farms followed up on McDonald’s cage-free purchase pledge with the announcement that it will add capacity to house 2 million cage-free layers at exiting Arizona locations.

“Cage free is just the next logical step in providing eggs to our markets and comfort for our hens,” CEO Glenn Hickman said. “Our customers are moving to cage-free faster than the regulatory environment is requiring it, so we want to ensure abundant supplies. It’s the future of our industry and our business.” Based on published reports, Hickman cage-free houses will use aviary systems.

On October 21, 2015, a ribbon-cutting ceremony marked the start of production at Red River Valley Egg Farm located near Bogota, Texas. This cage-free egg farm is a joint venture between Rose Acre Farms and Cal-Maine Foods, the two largest egg producers in the U.S.
The farm’s plan calls for an initial capacity of 1.8 million cage-free layers and the site is permitted for up to 3 million. The layers will be housed in convertible modules designed by Rose Acre Farms.

On October 13, 2015, Rembrandt Foods, the third-largest egg producer in the U.S. and one of the largest egg products suppliers, announced that all of its future farm projects would be cage free. The company had previously announced that it would construct a 7 million-layer facility which would come online in 2017.

Jonathon Spurway, vice present of marketing, Rembrandt Foods, said that the farm on the drawing board will now be cage free, but that it won’t house 7 million hens. “Any further investments will be aligned to cage-free as our standard,” Spurway said. “The company will have multiple large-scale investments come online.”

Spurway said Rembrandt doesn’t have plans to convert its houses with cages to cage free at this time.
“The industry isn’t going to switch to entirely cage free in the next 10 years,” he said. “Even foodservice outlets like McDonald’s that have made announcements have transitions over a number of years. We are moving quicker than I expected, but I am excited because it offers an opportunity.”

“The consumer is driving the behavior that, ‘I want cage-free eggs at a minimum.’ There is a segment of the population, and it is a large segment, that are willing to pay for cage free or whatever might drive them,” he added.

Forecast for more cage-free layers
The USDA doesn’t publish a forecast for the future size of the cage-free layer flock in the U.S., but industry sources suggest that the rapid growth in the number of cage-free layers seen in 2015 will continue into 2016. Sales of housing systems to U.S. egg producers have seen dramatic shifts in the past 10 years. A market that was dominated by sale of conventional cages saw a shift first to enriched/enrichable cages and now to cage-free systems.

Increasing demand for cage-free eggs in the U.S. has shifted investment in pullet and layer housing to cage-free systems. | Photo courtesy of Big Dutchman

Sources report that, for the first time in decades, the sales of cage-free housing systems in the U.S. in 2015, in terms of number of hens that can be housed, exceeded spaces sold for cage housing. This is expected to continue as sales of even “enrichable” cages fall to very low levels. If all of the cage-free systems that are expected to be installed by the end of 2016 were fully stocked, the U.S. would have about 19 million more cage-free layers then it had in September 2015. Because it can take a year or more to fully stock a large layer complex, these new projects will not all be fully housed by the end of 2016.

Other factors to consider

The U.S. table egg and egg products markets have traditionally been white egg and white bird markets. Cage-free customers in the U.S. have tended to prefer brown eggs, but as cage-free becomes more mainstream, expect a shift to white eggs, particularly for egg products.

All cage-free systems are not alike in how they allow the three-dimensional space inside a house to be utilized for housing hens. “Combi” or “convertible” systems will compete with aviary systems for share in the non-organic cage-free market. More traditional floor systems will likely continue to dominate the organic cage-free market, because they are more suitable for providing hens the required outdoor access.