CD40LG and enteritis: Effect of eggshell temperature (EST) during late incubation [≥embryonic day 17–19.5; 37.8°C (control) or 36.7°C (lower)] and/or feeding strategy after hatch [immediate access to feed and water (early) or 51–54-h deprivation (delayed)] on IgM and IgY natural antibody (NAb) titer against keyhole limpet hemocyanin of broilers at d 0, 6, or 14 post Eimeria inoculation (d 21 post hatch) to induce necrotic enteritis (LSmeans ± SEM).