Enrichments in broiler production

Do the levels of bird activity and comfort behaviours increase when enrichments are placed in broiler barns? Which enrichments do broilers prefer to interact with? Does providing enrichments result in improved health outcomes or impact on production parameters?

These are some of the main questions that Maple Leaf Foods is seeking to answer, and share with industry, in its quest to improve broiler welfare. 

In various published studies, enrichments have already been shown to provide birds with the opportunity to express natural behaviour. They also encourage increased activity, reduce fearfulnesss and improve leg health.

The enrichment trials initiated at Maple Leaf began in 2019 and two major studies have now been completed. “After the first trials, we changed the enrichment object design based on what we had learned,” explains poultry veterinarian Dr. Kathleen Long, who is vice president of animal care at Maple Leaf Foods. “We are working toward publishing all our trial results in a peer-reviewed journal.”

Why enrichments matter
The broiler industry is in general agreement that enrichments are one of four farm-level broiler welfare parameters that are of most interest to all stakeholders, some of which require more study, consensus and/or broader implementation. The others are lighting, stocking density and slow-growth breeds.

“The National Farm Animal Care Council Code of Practice for broilers is behind the laying hen and pig Codes in terms of enrichments, and we are keen to help inform the next update,” Long says. “I, our technical team and our farmers are seeing a lot of benefit to enrichments for the birds, and our farmers really enjoy seeing the birds interact with them.”

Maple Leaf Foods has already released to the public a large amount of detailed information about its broiler welfare practices, in both its annual Sustainability Report and Animal Care Performance Report. This year, across 150 companies in 25 countries, the Business Benchmark on Farm Animal Welfare ranked Maple Leaf Foods and 11 other firms in Tier 2, with only four in Tier 1. 

Enrichment power
Broiler enrichments can include hanging peck objects (e.g., washers tied to water lines with plastic ties), ramps, tunnels, perches, straw bales and pecking block products. Indeed, enrichments can be defined as any safe materials or objects added to the environment which engage the brain and encourage the expression of natural behaviour and exercise.

Maple Leaf made sure its selection of enrichments to study are best suited to commercial production, Long says. “In addition to the welfare benefits they offer birds, they were chosen to promote biosecurity and ease of cleaning,” she says. “They were also chosen for durability and cost.” 

Trial details
Trials were conducted on volunteer commercial broiler barns with average flock sizes of 27.000 birds, notes technical team member Jessica Walsh. “The first flock was used as a control flock adding no enrichments,” she says. “But taking behaviour and health measurements for comparison to flocks later provided with enrichments.”

In the first experiment of the first trial, a flock was given one pecking object and one perching object. These enrichments were placed in the barns at bird age of seven to 10 days (after the brood guard was down to avoid influencing chick start-up). However, impact on chicks was found not to be an issue. So, in subsequent trials, enrichments are added as soon as possible after chick placement. And Maple Leaf now recommends placing enrichments before chicks arrive. 

In trial two, flocks were given three hiding objects (e.g., tunnels), one perching object and one pecking object. Trial three involved three pecking objects.

Observation areas of the barns were established and six sets of behavioural observations were made every day. In addition, after each flock cycle was complete, scoring for any footpad or hock dermatitis was done, along with analysis of leg bone composition and comparison of leg weight relative to body weight. Production parameters (mortality, leg culls, feed conversion and condemns) were also measured.

Results
Overall, the broilers performed more active behaviour when provided enrichments. They also displayed more comfort behaviour (e.g., pecking, flapping).  

Most interactions happened with the four-inch perches, followed by the slatted ramps and, thirdly, with the two-inch perches. “Interaction means did they climb or jump up on the objects using their wings, did they perch on it, sit next to it, hide underneath it or peck at it,” explains Long. “We found that they liked to perch most on the slatted ramp.” 

In terms of pecking, the broilers liked the pecking blocks and straw bales most but also pecked objects not intended for pecking such as the tunnels.

In most treatments compared to no enrichments, there were fewer footpad and hock dermatitis incidences among the groups and better leg bone strength as well. There was no difference in food pad and hock health in the treatment with tunnels, grid ramp and hanging pecking objects compared to no enrichments. The same result was observed with the treatment with straw bales and a rung ramp, and the treatment with pecking blocks and two-inch perches.

Enrichment use also improved the relationship between leg bone composition and leg weight relative to body weight. There was no obvious trend in whether providing enrichments impacted any production parameters, such as mortality, condemns and feed conversion. 

Recommendations
At this point, based on their findings, Long and her team recommend enriching barns with the aluminum grid ramps (one-inch square grid) for perching behaviour and providing straw bales or tied washers to stimulate more pecking. 

“We recommend the aluminum grid ramp over wooden objects due to it being lightweight, easy to clean and durable over multiple flocks,” she says. “We also recommend tunnels, with holes for visibility, for birds to hide and rest in, which we have redesigned into stackable hiding huts.”  

The enrichments used in these trials were designed by Long and her team in collaboration with two companies in southern Ontario. Bridgeview Metal in West Montrose, Ont., manufactured the aluminum grid ramps, and Bluewater Pipe in Huron Park, Ont., designed and manufactured the trapezoid huts and tunnels. 

Looking forward, Long says, “We’re excited about our results, but we also view this as one step on our animal welfare journey.”