Effect of environmental temperature on immune response of broilers

Several studies demonstrate that environmental temperature can influence the immune response of poultry. The objective of this research was to determine at which stage in the life of a bird this effect is greatest. In experiment 1, broiler breeder eggs were incubated at three different temperatures (36.8+/-0.2, 37.8+/-0.2, and 38.8+/-0.2degreesC from the 13th day of incubation to hatching. After hatching, birds were raised in thermoneutral temperature. In experiment 2, 144 1-d-old broiler chicks were distributed into three environmental chambers with different temperatures (18+/-2, 24+/-2, and 32+/-2degreesC). In both experiments, the humoral immune responses to Newcastle disease virus (NDV) and infectious bursal disease (IBDV) were evaluated. NDV and IBDV antibody titers were not significantly different (P > 0.05) among treatments.