By Doug Schmitz
AMES, Iowa – According to Iowa State University researchers, periodically projecting randomly moving, dot-sized laser lights on the floor of broiler chicken pens stimulates the birds’ predatory instincts and encourages them to be more active, which, in turn, boosts their meat quality and welfare.
“We were concerned the birds would exercise more, be smaller and lose weight,” said Elizabeth Bobeck, Iowa State associate professor of animal science. “Instead, we found that they spent more time walking around and engaging in more positive behaviors that improved weight gain and bone density.”
Bobeck and Anna Johnson, Iowa State professor of animal behavior and welfare, partnered with Signify, an Eindhoven, the Netherlands-based livestock lighting company, to create a second-generation novel laser device for this research.
With support from the U.S. Poultry and Egg Association, the USDA and NIFA, Bobeck and Johnson conducted a study to assess how these laser devices influence animal behavior.
“I joined the animal science department at (Iowa State) in 2016 as an assistant professor,” Bobeck said. “Soon after I joined, I approached Anna with the observation that chicks interacted with (chased and pecked) infrared thermometer laser dots.
“I wanted to test this phenomenon in a research setting, but with my nutrition, immunology, and overall production type background, I wanted to make sure an ethologist was involved with the work,” Bobeck added. “Anna thought it was an interesting idea and agreed to write a grant with me. We submitted to the U.S. Poultry and Egg Association, received a grant to complete the work, and the rest is history.”
According to Bobeck and Johnson, broilers exposed to the lasers walked more frequently and for longer distances than their counterparts in the control group. They also spent more time at feeders and waterers, thus gaining more weight and improving their feed efficiency.
Despite their increased activity, the birds in the treatment group did not experience more lesions, scratches or blisters on their feet or bodies, Bobeck and Johnson said.
Bobeck and Johnson conducted subsequent studies to measure different aspects of broiler performance, meat quality and stress in response to this biologically relevant environmental enrichment from lasers.
In one experiment, they found the level of serum corticosterone, a stress hormone, in the broilers’ blood was actually lower when birds were exposed to the laser devices.
“We wanted to know if the laser was used: does it make the birds more anxious or frightened?” Johnson said. “The answer was no. One thing we were mindful about when creating the lasers is allowing the individual bird choice. If the broilers want to interact with the laser, they can. If they choose not to, they can do that, too. I think that is a real benefit from a welfare standpoint.”
Bobeck said the size and movement of the novel laser devices mimics small insects that chickens naturally want to chase; the lasers emit a red light to attract the birds’ attention, and ensure animal and human safety.
“We picked red because we knew it would be an enticing color for broilers, but also from a safety perspective,” Bobeck said. “Other laser colors, like green, have a more intense wavelength and can be more damaging to eyes.”
Unlike other forms of environmental enrichment for poultry, like perches and platforms, the laser devices do not need to be cleaned and sanitized between shipments of birds.
Johnson said this not only reduces the potential to spread disease, it also limits labor requirements.
“A device might need occasional tweaking or software upgrades, but for all intents and purposes, it will run on its own,” Johnson said. “That will be super attractive to producers.”
Over 30 Iowa State undergraduate students and several graduate students have been involved with the laser device research. The lasers are currently undergoing research trials at a commercial confinement to understand their utility at large operations.
Bobeck and Johnson said they believe this type of environmental enrichment can also benefit smaller flocks, as well as other types of poultry, such as turkeys and laying hens.
Bobeck said she and Johnson have been working on this project since 2016, and have seen many different types of benefits for the broiler chickens.
Bobeck said the benefits can be broken down into two categories: bird productivity and bird well-being.
“Both are important to the producer, and the bird,” she said. “We see performance benefits (i.e., better rate of gain and improved feed conversion rate); bone health benefits (i.e., denser and better quality tibia bone); and (we) have seen reduced muscle myopathies (i.e., woody breast and white striping) associated with laser-induced movement.
“From a behavior and well-being standpoint, we see birds moving farther and more often, going to the feeder and waterer more frequently, and (we) also do not see any increase in lameness or footpad issues that might be related to changing how much they move.”
Bobeck said, “It is important to note that we are giving the birds a choice to interact with this enrichment device: the moving laser dot,” she said. “This choice is important because we have found also that the birds are not stressed by the exercise (i.e. the movement is voluntary).
“From a producer standpoint, they have an option to add environmental enrichment and complexity to the environment without introducing a physical object that would need to be moved to work around, would need to be replaced with each flock, or could potentially be a disease vector (accelerator).”