Figure 2.

Survival curves of chickens challenged with distinct MDV strains over the 75-day experimental time period. For each experimental group, the birds were separately challenged with CEFs containing 2000 PFU viruses by intra-abdominal inoculation, while for the negative controls, a fifth group of birds were inoculated with an equal volume of mock-infected CEFs. Early deaths due to intra-abdominal infection adverse effects and birds sacrificed for body weighting and immune organ collections were excluded for data calculation.