Animal welfare indicators and stress response of broiler chickens raised at low and high stocking density

Stocking density is a crucial parameter that impacts animal welfare, performance, and economic returns for producers. In our current investigation, we explored the influence of stocking density on the growth performance, litter quality, footpad dermatitis, and corticosterone concentrations in broiler chickens. Low and high stocking densities were defined as 16.7 birds/m² (certified for animal welfare, n = 32,000; initial body weight [BW] = 42.1±0.32 g; Arbor Acres) and 20.3 birds/m² (commercial farm, n = 32,000; initial BW = 42.9±0.31; Arbor Acres), respectively. A basal diet typical of commercial standards was developed to meet or surpass the nutritional requirements outlined by the National Research Council (NRC) for broiler chickens. The control group was housed for 29 days to compare productivity and animal welfare indicators in high stocking density (20.3 birds/m²) as per livestock industry regulations and low stocking density (16.7 birds/m²) according to animal welfare standards. During the grower periods (21-29 days) and the overall period (0-29 days) of the experiment, feed intake and BW were lower in the lower stocking density group (p < 0.05). Additionally, the feed conversion ratio significantly improved at the lower stocking density. By day 29, the average footpad dermatitis score, litter moisture, NH₃ concentration, and feather cleanliness were significantly higher at the higher stocking density. Corticosterone concentrations decreased by 2.35% at the lower stocking density by day 29. These results indicate that decreasing stocking density enhances the welfare and growth performance of broiler chickens, as indicated by decreases in litter moisture, footpad dermatitis, and corticosterone concentrations.