Table 2.

Cumulative morbidity, mortality, and gross tumor incidence in birds challenged by different MDV strains calculated at 75 days post-challenge (dpc).

No.	Strains	Total Numbers a	Diseased Birds	Morbidity (%) b	Deaths	Mortality (%) c	Gross Tumors	Tumor Incidence (%) d
1	HN502	37	13	35.14	5	13.51	10	27.03
2	HN302	31	31	100.00	17	54.84	27	87.10
3	HN304	37	5	13.51	2	5.41	3	8.11
4	HN101	32	7	21.88	2	6.25	5	15.63
5	CEF	35	0	0.00	0	0.00	0	0.00

^a Total number = number of virus-challenged birds in each group-total number of birds necropsied for weighting (15)-number of non-pathologically death. ^b All the birds showing clinical MD symptoms, death and survivals with gross tumors were classified as MD cases. Morbidity (%) = number of MD cases/total number × 100. ^c Mortality (%) = number of death/total number × 100. ^d Tumor incidence (%) = number of deaths or survivals with gross tumors/total number × 100.