Dr. Elizabeth Bobeck and colleagues at Iowa State University in Ames, Iowa, recently completed a research project that examined the feasibility of using a novel laser device in a broiler house to stimulate enhanced bird activity, according to an announcement from the U.S. Poultry & Egg Assn., which funded the research.

According to a research summary by Bobeck, today's broiler spends much of the day inactive, while physical activity has been shown to improve leg health and reduce lameness. To promote movement, environmental enrichment may be added to broiler houses; however, few published studies have been able to show a positive effect of enrichment on bird activity without sacrificing performance outcomes, she said.

The novel laser environmental enrichment device was implemented throughout a six-week growout cycle. Bobeck explained that the research group hypothesized that the laser would stimulate natural predatory behavior in the broilers that, in turn, would increase locomotion and feeding. They further hypothesized that the broilers' leg health and growth rate would improve due to increased movement throughout the growth period.

Bobeck said the study's objectives were to: (1) validate quantitative methods to evaluate broiler bird welfare, specific to production (performance, leg lameness, breast blisters, footpad dermatitis, ammonia production, litter quality, behavior and movement outcomes), and (2) evaluate experimental environmental enrichment using quantitative methods verified in objective 1.

According to the research summary, the tested laser enrichment device not only significantly increased broiler activity (weeks 2-5) but improved performance outcomes including feed intake and weight gain, average daily gain and feed conversion ratio. Importantly, measures of bird welfare — including gait score, contact dermatitis score, tibia quality and air and litter quality — were not negatively affected by laser treatment, Bobeck wrote.

The consistent increase in weight gain observed in the laser-enriched birds averaged to a greater end weight of 0.24 kg per bird on day 42. Improved feed conversion (a significant 18-point decrease in the finisher period) translated to a reduction in feed costs of greater than 5%, Bobeck said.

She noted that the laser device was practical to implement in commercial barns and did not require altered management or bird contact, allowing for ease of cleaning and use over multiple flocks.

Based on the utility of measures studied through objective 1, Bobeck said a simplified measure of broiler behavior and quantification of distance walked are recommended in the commercial audit. Further, a novel gait-scoring platform tested in this study is recommended for research and commercial use; for example, measures of contact dermatitis should be adapted to include on-farm scoring, but measures of bone quality are suitable for research only.

Bobeck added that, through the research study, recommendations were made for producers that can be used on farms to measure broiler welfare, and recommendations were also made for updating currently used broiler welfare audit guidelines.