Prevalence of Salmonella spp. in Breeding Flocks, Laying Hens and Broilers in Different Regions of Bulgaria in 2016

Abstract

In 2016 a total number of 297 samples were tested in the frame of Salmonella control programmes in Bulgaria including official control (n = 101) and control by the business operators (n = 196). The samples originated from 3 categories of hen flocks: 48 pcs. samples from breeding flocks, 175 pcs. from laying hens and 74 pcs. from broilers. The samples belonged to 3 different groups: I – fresh feces, boot swabs and fabric socks swabs (n = 281), II – dust samples (n = 10), and III – egg shells (n = 6). The laboratory tests were performed in accordance with EN ISO 6579: 2003/À1:2007. Salmonella positives were found in 40% of dust samples (n = 10) and 2.09% of fresh feces, boot swabs, fabric socks swabs, and egg shells (n = 287). The percentage of Salmonella spp. positive samples was 3.37%, including 0.67% of breeding flocks and 2.69% of laying hens. The prevalence of Salmonella in breeding flocks was 4.17% and among laying hen herds – 4.57%. There was no Salmonella spp. detected in broilers.

The ratio of isolated Salmonella serovars was: Enteritidis – 60%, Senftenberg – 20%, and Corvallis and Infantis – 10%. In total 6.93% of the samples tested for official controls (n = 101) and 1.53% for business operator control (n = 196) were positive for Salmonella. It is recommended the replacement of dust samples with another type of sample to be solely as an exception and the control of Salmonella spp. in samples from the primary production to be as much as possible under the official control.