Table 1.

Numbers of tested farms by administrative districts.

Administrative District	Number of Sampled Farms	Total Pooled Samples per Districts
Montana	2	40
Vratsa	1	20
Lovech	2	40
Gabrovo	1	20
Ruse	5	100
Razgrad	4	80
Shumen	2	40
Varna	3	60
Pazardzhik	4	70 *
Stara Zagora	4	80
Yambol	4	80
In total	32	630

* In Pazardzhik district, only 10 samples were collected (from dry sows and gilts) from a farm, as no finishers were present at the moment of sampling.