Lesions of velogenic viscerotropic Newcastle disease virus infection were more severe in broilers than pullets

Figures & data

Table 1. Mean of body weights of control and VNDV-infected birds (g) ± SEM.

Group	Days PI		% weight loss
	0	4	%
Pullet control	735 ± 36.8	797.8 ± 35.8
Pullet infected		636.2 ± 33.4*	20.26
Broiler control	2870 ± 183.0	3445 ± 152.0
Broiler infected		2113 ± 203.6*	38.66

Notes: Means with asterisks are highly significant. Lower than their controls (P < 0.05).

SEM = Standard error means to the mean values of control and infected.

Table 2. Comparison of the cumulative mortality rate of broiler and pullets challenged with vvNDV.

Days PI	Mortality Rates
	Pullet	Broiler
1	0/30 (0%)	0/30 (0%)
2	0/30 (0%)	0/30 (0%)
3	5/30 (17.8%)	6/30 (20%)
4	21/30 (70%)	19/30 (63.3%)
5	30/30 (100%)	30/30 (100%)

Note: No significant differences between the mortality rates (P > 0.05).

Figure 1. (A) Proventriculus of VNDV infected broilers showing severe mucosal haemorrhages on day 4 PI. (B) Proventriculus of VNDV infected pullets showing mild mucosal haemorrhages on day 4 PI.

Figure 2. (A) Intestines of VNDV infected broilers showing severe haemorrhagic ulcers in broilers on day 4 PI. (B) Intestines of VNDV infected pullets showing less severe ulcers on day 4 PI.

Figure 3. (A) Caecum of VNDV infected broiler showing severe swollen hemorrhagic tonsil on day 4 PI. (B) Caecum of VNDV infected pullet showing less severe lesion on the tonsil on day 4 PI.

Figure 4. (A) Severe atrophy of the bursa of VNDV infected broilers on day 5 PI. (B) Less severe atrophy of the bursa of VNDV infected pullets on day 5 PI.

Figure 5. (A) Severe necrosis and depletion of lymphocytes in the bursa of VNDV infected broilers on day 4 PI. H&E × 400. (B) Less severe necrosis and depletion of the lymphocytes in the bursa of VNDV infected pullets on day 4 PI H&E × 400.

Figure 6. (A) Thymus of VNDV infected broiler showing severe necrosis and depletion of lymphocytes on day 4 PI. H&E × 400. (B) Thymus of VNDV infected pullet showing less severe necrosis and depletion of lymphocytes on day 4 PI. H&E × 400.

Figure 7. (A) Spleen of VNDV infected broiler showing severe lymphocytic depletion and fibrin deposition on day 4 PI. H&E × 400. (B) Spleen of VNDV infected pullet showing less severe lymphocytic depletion and fibrin deposition on day 4 PI. H&E × 400.

Table 3. Comparison of gross lesion scores of pullets and broilers challenged with vvNDV on day 4PI.

S/No	Proventricular Haemorrhage		Intestinal Ulcers Haem		Caecal Tonsil Haem
	Broilers	Pullets	Broilers	Pullets	Broilers	Pullets
1	2	1	2	1	2	1
2	3	2	2	2	2	1
3	2	2	3	2	2	2
4	2	2	3	1	2	1
5	3	1	2	2	3	1
6	2	1	2	2	3	2
7	3	2	2	2	2	2
8	3	2	3	1	2	2
9	3	2	3	2	2	1
10	3	1	2	1	2	1

Note: Mean 2.60 ± 0.52^b, 1.60 ± 0.52^a, 2.40 ± 0.52^b, 1.60 ± 0.52^a, 2.20 ± 0.42^b, 1.40 ± 0.52^a.

^a,bDifferent alphabetical superscripts in a row indicate significant difference (p < 0.05) between the mean scores of the lesions in broilers and pullets.

Table 4. Virus isolation in pooled organs on day 3 PI.

ORGANS	HI ACTIVITIES
Spleen	+
Thymus	+
Intestine	+
Bursa of Fabricius	+

+ = Virus isolated.