TABLE 1.

Description of serological and microbiological sampling^a

Type of hen and farm sampledb	No. of sera testedc	No. of eggs sampledd	Vaccinatione
Layers
A	189	1,200	No
B	183	600	9R
C (5 flocks)	949	800	9R
D	189	600	No
E	186	700	No
F	0	600	NA
G (2 flocks)	339	600	No
H	181	700	No
I	0	500	NA
J	0	500	NA
K	183	500	No
L	189	700	No
M	0	400	NA
N	191	600	SEI
Ñ	198	400	No
O	0	400	NA
P	0	500	NA
Q	181	400	No
R	0	700	NA
S	182	600	No
T	189	400	No
7	185	0	No
Layer-breeders
14	153		No
19	139		No
20	151		No
26	99		9R
27	99		9R
30	149		No
31	151		No
33	168		No
34	157		No
Broiler-breeders
2	150		9R
3	153		No
4	158		SEI
25	160		9R +SEI
32	150		SEI

^aData from environmental and cloacal swabs are not included. Each flock was sampled for 60 cloacal swabs and 1 environmental swab.

^bA total of 41 flocks were tested.

^cA total of 5,751 sera from 34 flocks were tested.

^dA total of 12,400 eggs from 21 layer farms were tested.

^eNA, no available data. 9R, S. Gallinarum rough strain 9R vaccine. SEI, S. Enteritidis inactivated vaccine.