Effects of Environmental Enrichment on Behavior and Space Use in Cage-Housed Laying Hens
Academic Level at Time of Presentation
Senior
Major
Animal Science
List all Project Mentors & Advisor(s)
Dr. Thomas H. Powell, PhD
Presentation Format
Poster Presentation
Abstract/Description
Effects of Environmental Enrichment on Behavior and Space Use in Cage-Housed Laying Hens
Emily F. McManaway, Natalia Cummings, Thomas H. Powell, Tyler L. Summers, Kali Schurmeier, Lily Denning, Cameron Hawkins
Murray State University, Animal and Equine Science, Murray, Kentucky USA 42071
This study evaluated the effects of environmental enrichment on damaging behaviors, non-damaging behaviors, and space use in commercial white egg–laying hens (Hy-Line) maintained in a cage-housed environment. It was hypothesized that enrichment would reduce damaging behaviors and alter behavioral time budgets and cage space use. Approximately 42-wk-old hens (n = 20) were assigned to one of four treatments over a 5-wk period: control (no enrichment), dust bath, mirrors, and turf, with each treatment consisting of a single cage containing five individually identified hens. Observations were conducted three days per week at consistent times of day to minimize diurnal variation. During each observation period, hens were monitored for one hour, with trained observers assigned to specific cages for 30-min intervals. Behavioral data were collected using a standardized ethogram including feeding, drinking, resting, preening, and general activity. Scan sampling at 2-min intervals during 30-min sessions was used to record hen location and behavior, while continuous event sampling was used to record ethogram events including chases, feather pecks, aggressive pecks, and interactions with enrichment devices. Prior to data collection, observers completed training and calibration sessions to ensure inter-observer reliability. Feeding schedules were standardized across all treatments, with hens fed once daily to reduce management-related variability. Scan data were analyzed as binomial proportions, and event data were analyzed using generalized linear mixed models (PROC GLIMMIX) with a negative binomial distribution. Models included treatment, week, and their interaction, with hen included as a random effect. Significance was declared at P < 0.05. Feather pecking was not affected by treatment (P = 0.3626) but changed over time (P < 0.05), with no treatment × week interaction (P > 0.05). Aggressive pecking differed among treatments (P = 0.0002) and over time (P < 0.0001), with lower counts observed in mirror and turf treatments compared with control and dust bath treatments, and no treatment × week interaction (P = 0.9932). Space use and other non-damaging behaviors were influenced primarily by week rather than treatment. Dust bathing was observed only in hens provided with dust bath enrichment.In this preliminary study, environmental enrichment was associated with reduced aggressive pecking in mirror and turf treatments, whereas feather pecking and other behaviors were influenced primarily by time. Given the limited replication (1 cage per treatment), these findings should be interpreted cautiously, and additional research is needed to confirm these observations and account for cage-level variation.
Keywords: laying hens, enrichment, aggressive pecking, behavior, welfare, pilot study
Spring Scholars Week 2026
Sigma Xi Poster Competition
Effects of Environmental Enrichment on Behavior and Space Use in Cage-Housed Laying Hens
Effects of Environmental Enrichment on Behavior and Space Use in Cage-Housed Laying Hens
Emily F. McManaway, Natalia Cummings, Thomas H. Powell, Tyler L. Summers, Kali Schurmeier, Lily Denning, Cameron Hawkins
Murray State University, Animal and Equine Science, Murray, Kentucky USA 42071
This study evaluated the effects of environmental enrichment on damaging behaviors, non-damaging behaviors, and space use in commercial white egg–laying hens (Hy-Line) maintained in a cage-housed environment. It was hypothesized that enrichment would reduce damaging behaviors and alter behavioral time budgets and cage space use. Approximately 42-wk-old hens (n = 20) were assigned to one of four treatments over a 5-wk period: control (no enrichment), dust bath, mirrors, and turf, with each treatment consisting of a single cage containing five individually identified hens. Observations were conducted three days per week at consistent times of day to minimize diurnal variation. During each observation period, hens were monitored for one hour, with trained observers assigned to specific cages for 30-min intervals. Behavioral data were collected using a standardized ethogram including feeding, drinking, resting, preening, and general activity. Scan sampling at 2-min intervals during 30-min sessions was used to record hen location and behavior, while continuous event sampling was used to record ethogram events including chases, feather pecks, aggressive pecks, and interactions with enrichment devices. Prior to data collection, observers completed training and calibration sessions to ensure inter-observer reliability. Feeding schedules were standardized across all treatments, with hens fed once daily to reduce management-related variability. Scan data were analyzed as binomial proportions, and event data were analyzed using generalized linear mixed models (PROC GLIMMIX) with a negative binomial distribution. Models included treatment, week, and their interaction, with hen included as a random effect. Significance was declared at P < 0.05. Feather pecking was not affected by treatment (P = 0.3626) but changed over time (P < 0.05), with no treatment × week interaction (P > 0.05). Aggressive pecking differed among treatments (P = 0.0002) and over time (P < 0.0001), with lower counts observed in mirror and turf treatments compared with control and dust bath treatments, and no treatment × week interaction (P = 0.9932). Space use and other non-damaging behaviors were influenced primarily by week rather than treatment. Dust bathing was observed only in hens provided with dust bath enrichment.In this preliminary study, environmental enrichment was associated with reduced aggressive pecking in mirror and turf treatments, whereas feather pecking and other behaviors were influenced primarily by time. Given the limited replication (1 cage per treatment), these findings should be interpreted cautiously, and additional research is needed to confirm these observations and account for cage-level variation.
Keywords: laying hens, enrichment, aggressive pecking, behavior, welfare, pilot study