Behavioral and welfare responses of broiler chickens to plastic-grid flooring, zeolite, and wood shavings litter systems.

This study evaluated the effects of different litter systems-plastic-grid flooring, wood shavings, and zeolite-enriched shavings-on the behavioral, welfare, and physiological responses of broiler chickens. A total of 504 one-day-old Ross 308 male chicks were randomly assigned to three flooring treatments, each with four replicates of 42 birds. Housing conditions consisted of conventional wood-shavings litter, a raised plastic-grid flooring system, and a zeolite-supplemented wood-shavings mixture. At 42 days of age, welfare and physiological parameters were assessed in 120 birds (10 per replicate), including tonic immobility and heterophile-to-lymphocyte ratios. Zeolite-enriched litter resulted in significantly lower ambient ammonia concentrations (P < 0.001). Behavioral observations revealed that broilers on plastic-grid floors performed less dust bathing but more stretching (P < 0.001), whereas zeolite litter increased pecking activity, suggesting substrate-dependent modulation of comfort and exploratory behaviors. Significant differences were also found in footpad dermatitis (P = 0.001) and plumage cleanliness (P = 0.007). Plastic-grid flooring reduced podiatric lesions and improved hygiene but restricted natural behavior, while zeolite improved air quality but increased footpad damage. Neither tonic immobility nor heterophile-to-lymphocyte ratios differed significantly among groups, indicating comparable physiological stress levels. Overall, these results highlight that litter materials distinctly influence environmental hygiene, behavioral expression, and integumentary welfare. The findings underline the importance of developing flooring systems that balance hygienic advantages with behavioral and welfare needs to achieve optimal broiler welfare and productivity.