Egg:embryo weight ratio as an indicator of dwarfism induced by infectious bronchitis virus

Figures & data

Table 1. Mean embryo egg weight ratios of IBV-inoculated embryonated chicken eggs at different days p.i.

Day p.i.	IBV H120	IBV 008	Uninoculated control
1	0.089±0.012^a	0.081±0.006	0.073±0.007
2	0.144±0.004	0.141±0.005	0.137±0.005
3	0.187±0.016	0.163±0.017	0.179±0.009
4	0.231±0.030	0.119±0.027^b	0.298±0.039
5	0.227±0.012	0.125±0.009^b	0.345±0.012
6	0.197±0.110	0.135±0.031^b	0.370±0.055
^aMean±standard deviation.
^bValues differ significantly from the respective day's EE ratio of uninoculated control eggs. Student's t test (P<0.05).

Table 2. Infectious bronchitis virus titration: EE ratios of chicken eggs inoculated with IBV at different dilutions^a

Log 10 dilution	IBV H120	IBV 008	Uninoculated control
−1	0.131±0.019^a (0.366)	0.143±0.023^a (0.401)
^−2	0.136±0.018^a (0.382)	0.165±0.010^a (0.463)
^−3	0.133±0.020^a (0.372)	0.156±0.043^a (0.437)	0.357±0.048
^−4	0.364±0.003^b (1.02)	0.202±0.099^a (0.567)
^−5	0.339±0.033^b (0.951)	0.355±0.021^b (0.992)
^−6	0.397±0.038^b (1.11)	0.372±0.040^b (1.043)
^−7	0.324±0.017^b (0.907)	0.336±0.013^b (0.941)
^−8	0.353±0.020^b (0.989)	0.353±0.056^b (0.990)
^−9	0.357±0.021^b (1.00)	0.367±0.028^b (1.03)
^aMean±standard deviation (EE indices in parentheses). Within the group, the EE ratios with different superscripts differ significantly in Student's t test (P<0.05).

Table 3. Mean EE ratios of embryonated chicken eggs inoculated with antisera against different isolates of IBV and 100 EID₅₀ H120 vaccine strain

	Reciprocal serum dilution used with 100 EID 50 of IBV H120
Serum against IBV	640	1280	2560	5120
H120	0.251±0.004^a (2.21)	0.239±0.013 (2.10)	0.247±0.022^c (2.17)	0.118±0.004 (1.04)
008	0.252±0.040 (2.21)	0.253±0.029^c (2.22)	0.149±0.079 (1.31)	0.119±0.015 (1.04)
S3	0.233±0.020 (2.04)	0.238±0.024^c (2.09)	0.115±0.007 (1.01)	0.120±0.005 (1.05)
U4	0.227±0.005^c (1.99)	0.123±0.012 (1.09)	0.113±0.010 (0.995)	0.113±0.007 (0.990)
177	0.237±0.006 (2.08)	0.246±0.009^c (2.16)	0.116±0.011 (1.01)	0.121±0.025 (1.06)
No serum	0.114±0.006
^aMean±standard deviation (EE index(VN)).
^cReciprocal of endpoint dilution showing complete neutralization of 100 EID50 H120 vaccine strain of IBV as assessed by the EE ratio.