Effects of stocking density and litter material on carcass characteristics, immune response, and litter microbial load of broiler chickens

To evaluate the effects of stocking density and litter material on carcass characteristics, immune response, and litter microbial load of broiler chickens, 2016 day-old broilers (Ross 308, as-hatched) in a period of 45 days by using a factorial experiment (3×2) in the randomized complete block design were assigned to three levels of stocking densities, including 10, 14, and 18 birds/m2 (equivalent 25, 35, and 45 kg/m2 live weight, respectively) and two types of litter materials, comprising wood shaving and paper roll. Immune responses were evaluated against phytohemagglutinin injection at day 43 of age and antibody titer against Newcastle disease at the days 10, 22, and 45 of the research. Carcass yield and cuts at day 44 and litter total bacterial count at day 45 of experiment were measured. Results showed that there were no significant differences on experimental days in immune Responses, and litter microbial load among treatments in interactions and main effects (P < 0.05). Microbial load of litter, numerically in 10 birds was lower as compared to others. The relative weight of gizzard was significantly (P < 0.05) higher in the birds were raised on wood shaving than that of birds raised on paper roll. In conclusion, stocking densities and litter materials used in this research had no significant effect on litter microbial load and immune responses of broilers.