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Pullet Training: Learning to thrive

The art (and science) of rearing pullets for aviary housing.


November 25, 2021
By Madeleine Baerg

Topics
More and more producers are raising pullets in aviary-style training systems so that they’re better prepared to navigate multi-level housing. PHOTO CREDIT: Big Dutchman

More and more egg producers are shifting to aviary-style layer barns. But preparing pullets to navigate a multi-level housing system isn’t as easy as loading conventionally raised birds into a barn and assuming they’ll figure out each component of the system. 

In fact, raising pullets for success in an aviary barn depends on a labour-intensive, step-by-step process to help young birds learn how to focus upwards, move through perching and nesting levels, access resources and live amongst a flock. It’s a job – a big job – that many egg producers are taking on for themselves as they realize the benefits of well-prepared pullets. 

Richard Boer of Brightside Poultry in Chilliwack, B.C., has produced organic eggs since 2017. Until per-bird space regulations changed in 2019, he ran his flocks in shallow pit slat-floor barns. To meet the new requirements in the most cost- and space-effective manner, he built his first aviary style layer barn in 2019: a 16,000-bird barn featuring the Dutchman Natura Step system. 

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The plan from the start was that he’d build a 16,000-bird pullet training barn alongside just as soon as the layer barn was complete. However, building the layer barn first meant that his initial flock of layers, rather than being raised in an aviary training barn, was custom-raised for him by a local farmer using a more conventional floor system. The experience – one he says he has no intention of ever repeating – convinced him of the absolute necessity of aviary-reared pullets. 

“We knew it would be a struggle, but it was more than a struggle,” Boer says. “There were so many floor eggs. So many. Picking up floor eggs was a full-time job in and of itself. When you know how bad it can be, everything since then has seemed much easier.”

In fact, Boer was lucky that floor eggs were his biggest challenge. Birds that don’t know how to navigate an aviary system can have difficulty finding feed and water, may not distribute well throughout the system and can end up crowding and crushing in certain zones of the barn. While floor eggs are a challenge and a frustrating cost, starvation and crushing can decimate returns. 

Today, Boer’s pullet barn is up and running, supplying all the new hens his aviary laying barns require. He uses the Natura Primus pullet aviary system: a system that keeps the birds caged until between four and five weeks, when the fronts of the cages open and ramps allow the young pullets access to outside perches, the barn floor and other levels. 

He says a few birds figure out flapping and moving throughout the system almost as soon as the cage doors open. By 11 to 13 weeks, virtually all are moving comfortably between the floor, the perching levels and the middle nesting box level. 

On the other side of the country, David Lefebvre operates a similar system in his pullet aviary barns at Ferme St-Ours Inc. in Montérégie, Que., with the help of farm manager Joel Ramos. Lefebvre runs: two 20,000-bird and one 50,000-bird free-run aviary layer houses; a 20,000-bird and a 50,000-bird free-run aviary-style pullet house alongside; two 10,000-bird organic aviary layer houses with a matched 10,000-bird free-run aviary pullet house; and a dozen 5,000-bird organic nest layer houses with six 5,000 organic one-floor pullet houses. 

Baby steps
Ramos and Lefebvre start their aviary chicks on the lowest level of their three-level cage system, then split half of them up a level at 10 days to provide adequate space. At 28 days, they install ladders from cages to the floor, then open the doors of the cages. 

For the first two weeks after the cage door opens, Boer at his farm in B.C. and Ramos and a team of workers at their farm in Quebec walk through their barns each night after the lights are turned off to lift birds into the system.  

“The first few days, it takes about three people a full hour for the 20,000-bird aviary pullet house,” Ramos says. “The rest of the first week, it’s about 45 minutes for three people. The second week, it’s about 15 to 30 minutes. Day after day, we have less birds on the floor until 99 per cent of them are in the system after two weeks.”

Full access
Once the two-week initial training is complete, the birds are given access to the entire system. 

At 12 weeks, Ramos begins to gradually remove ladders to force birds to use their wings to get up into the system. “In the white layer barns, we don’t have ladders, both because we prefer not to have them in the way and because it’s better for the birds to be flying and climbing. Also, we don’t want the birds going from the top of the system to the bottom and skipping the nest.” 

However, in the organic brown aviary-style layer houses, they do install their own, home-designed ladders, so that the birds are forced to walk in front of the nest to discover them faster and more easily. “The brown birds fly less than the white ones and prefer to walk. They do need ladders, even if we take the ladders off in the pullet house,” Lefebvre says. 

Lighting critical
The single most critical piece of management is lighting, all three producers agree. “We want to reproduce the sunset and sunrise. The birds follow the last light, so you give them the last light in the system where you want them to go,” Lefebvre says.

Of course, it’s not quite as simple as that. Each flock is different, so optimizing lighting and other management strategies depends on careful and constant adjustment. 

“The secret is observation,” Ramos says. “There are a general set of principles but with lighting and so many things, we respect the guidelines but the details we modify ourselves.”

Raising one’s own pullets
There’s no question that training the birds for aviary success is a lot of work. However, all three producers say there are obvious benefits to rearing one’s own layers. 

Boer says raising his own birds gives him better control over rearing. When he ordered flocks from a grower, he never knew exactly what would show up. “You didn’t know if the flock would be super flighty. The number you ordered was never the same as what you got.”

Also, he’s saving money through lower mortality. To reach the same ultimate size of laying flock, he typically orders two per cent fewer chicks for his aviary rearing program than for his one-floor system. 

Most importantly, all three producers truly enjoy working in the aviary environment. “To see the birds use the aviary, jumping up and flapping around, with everyone perching and sleeping on the top row at night – it’s pretty cool to see them moving around and being birds,” Boer says.

Ramos and Lefebvre agree. “When you’re in the barn, you’re in the birds’ place. It’s a completely different atmosphere. It’s really great to see the birds benefit and take advantage of that liberty,” Ramos says. 

“We hope that in time we get the premium for all our free-run eggs but, even if we don’t, we like this [production style],” Lefebvre says.

Time in the barn
Boer and Ramos agree: no matter what production system you choose, success depends on hours spent in the barn, both at the pullet rearing and the layer stages. 

Boer recommends making noise, moving freely and letting the pullets get to know you as you get to know them. He intentionally walks wherever he feels like through the barn. He often sings along to the music he’s listening to on his earbuds. 

“The more they’re used to movement and noise, the calmer and less flighty they are,” he says. “You can never spend enough time in the barn.”

He also thinks movement gets them up and moving. “Every time you go through the barn, you activate them. They want to see who it is; they’re getting up; they’re following you. Rather than having birds that just sit there on the floor, it gets them moving. They see other birds using the ramps and it helps them figure out how to get up into the system.”

What new research says
Ana Rentsch, a PhD student at the University of Guelph, is researching how best to raise a pullet for future success in an aviary barn. Between the summer of 2019 and May of this year, she raised four flocks of laying hens. Together totalling 12,000 birds, the flocks were raised in one of three aviary-systems or a conventional cage. 

The aviary systems differed in the amount of spatial complexity the birds had access to in their very first weeks of life.  The simplest system consisted of a small cage that housed approximately 115 birds and included a feeder, a drinker and a single perch. 

The intermediate system consisted of slightly larger cage that housed approximately 140 birds and added an elevated level and more perches (typically three). 

The highest-complexity system was a grid system that housed approximately 600 birds and allowed access to the whole length of the barn. In this system, the birds had access to an elevated platform through the middle of the barn, as well as five to six perches. Once chicks were six weeks of age, all systems were opened up to offer pullets a litter area and multiple system tiers.

Not surprisingly, the conventional and simple aviary systems allowed the easiest access to food and water, whereas the open-concept system led to more navigation challenges. 

“We do see manageability issues in more complex spaces, as it is challenging to start chicks when they are not as confined,” Rentsch says. “It is possible to manage but it requires more thought and effort.”  

In terms of physical development, the birds reared in aviaries developed better than birds raised in conventional rearing systems. To date, she has not yet found conclusive evidence that there are physical differences between pullets raised in the different aviary systems. 

However, clear behavioural differences exist, some of which may impact physical health in the long-term. 

“What I found is that in the middle-complexity system, we see more dynamic load-bearing behaviours – things that strain bones and end up developing those bones – than in the simple system. And in the most complex system, it’s more again. Also, white pullets perform more dynamic load bearing behaviours than brown ones in all systems,” she says. 

The most obvious bone-density building activity in the open-concept barn is running: several times each day, virtually all of the chicks would run from one end of the barn to the other, often flapping their wings along the way. 

“They run back and forth a few times and then they go back to doing what they were doing before. We don’t know why they do it, but it is a very commonly occurring behaviour when [birds are] given the space to perform it,” Rentsch says. “There seem to be many different triggers, but it doesn’t have to be stressful.”

Meanwhile, birds in more complex aviaries develop better cognitive function, Rentsch’s research shows. When the birds reached 13 weeks of age, Rentsch tested their learning skills in a puzzle: a simple T-shaped maze with a reward at one end. She found that the birds raised in the mid- or high-complexity barns consistently found the reward faster than birds raised in the simple system.

“While [the test] is not enough alone to say they have better spatial ability, birds from the more complex systems do seem to learn faster. What it could mean is that if you put those birds into an adult aviary, they could learn where the resources and the nest boxes are quicker,” Rentsch says. 

Interestingly, she found birds raised in the simplest aviary system were no better at finding rewards in the T-maze than birds raised in a conventional cage.   

Her results did vary. She says the most interesting result was that Lohmann Selected Leghorns lites (whites) consistently used spatial opportunities more than the Lohmann Browns lites, were faster at learning resource locations and seemed more physically able to perform certain skills, regardless of rearing system. 

Rentsch does not have final data collected on the long-term impacts of rearing styles yet. Among other upcoming results, she hopes to soon have analysis from x-rays data to determine if rearing differences ultimately result in changes to the keel-bone fracture rate in adult hens. 

That said, certain existing research may help producers as they make aviary system purchasing decisions. For example, research from past studies definitively shows that birds benefit from being raised with access to perches from day one onwards. 

Not only does early perching help them navigate vertical space, it reduces feather pecking, cannibalism and floor eggs in adult hens, Rentsch says.  

There is another critical factor, however. Each specific farm has different management needs and priorities. 

“We could build an aviary that’s a paradise for a chicken but it’s not feasible for a farmer,” she says. “Ultimately, whatever system one chooses, it has to work for the producer.”  


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