Effect of Stocking Density on Health of Broiler Chickens: A Comprehensive Review

The health performance of broiler chickens is influenced by various factors, including farm management practices and environmental conditions. However, limited information exists on the relationship between stocking density and broiler health outcomes under commercial conditions. This systematic review aimed to evaluate the impact of different stocking densities on broiler health indicators. Following the Preferred Re-porting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted using databases such as Scopus, Science Direct, and Google Scholar, covering studies pub-lished from 2000 to 2021. This review addresses a critical gap by systematically evaluating how stocking density affects broiler health through clinical, hematological, and stress-related indicators across different housing systems. The results indicated that the average low and high stocking densities were 11 birds/m² and 17 birds/m², respectively. Broilers reared at lower stocking densities consistently exhibited better health outcomes, including lower scores for gait abnormalities, footpad dermatitis, hock lesions, and breast blis-ters. Furthermore, reduced stocking densities were associated with lower heterophil-to-lymphocyte ratios, corticosterone concentrations, and mortality rates. In conclusion, the evidence consistently demonstrates that lower stocking densities improve broiler health and welfare across diverse management systems.