Fig. 2

The second immune development pattern of broiler chickens housed in laminated cages is Up-Down. The frequencies of mononuclear/macrophage (a) and Th cells (b) of peripheral blood lymphocytes were analyzed by flow cytometry. Peripheral blood lymphocytes were stimulated with concanavalin A (ConA) (c) or lipopolysaccharide (LPS) (d), and the stimulation index (SI) was calculated as described in the Materials and Methods section. The mRNA levels of CD4 (e), IgA (f) and TGF-β1 (g) were analysed by RT-PCR. Different small letters on the bars indicated significant difference (P < 0.05)