No abstract

Microbial pathogens of the genus Salmonella are among the leading causes of foodborne illness in the world. The present study was done on a laying hen farm with a Salmonella enterica serovar Enteritidis-positive result according to the testing specified by European regulation 2160/2003. The aim of this study was to compare the Salmonella contamination on a laying hen farm with the Salmonella presence in the hen eggs. The strains were isolated by ISO method 6579:2002 (standard method for the detection of Salmonella spp. in the European regulation for food and animal feeding stuffs, animal feces, and environmental samples from the primary production stage, including poultry farms) and were confirmed as Salmonella Enteritidis by the Kauffmann-White method. In addition, strains were compared with genomic macrorestriction followed by pulsed-field gel electrophoresis. Four types of samples, namely, feces (n = 50), cloacal swabs (n = 150), eggshells (n = 50), and egg contents (n = 50), were taken from each of 50 randomly selected battery cages. Results demonstrated that feces (92%) were the most positive sample, followed by eggshells (34%) and cloacal swabs (4%). No Salmonella spp. were detected in the egg contents. Our results show that a Salmonella Enteritidis-positive result on a laying hen farm, according to the testing specified by European regulation 2160/2003, did not imply the presence of the pathogen in the egg contents. Additionally, XbaI-digested genomic DNA of Salmonella Enteritidis strains isolated from several samples resulted in the same pattern, so were probably of the same origin.

No abstract

No abstract

The aim of this study was to assess the effect of carvacrol supplement as a dietary additive to rumen fermentors, fed a barley seed:alfalfa hay (70:30) ration and to compare its effect with monensin supplementation. The material was incubated with goat ruminal fluid and four different treatments were included: no additive (C), 7.5 mg/l monensin (M), 250 mg/l carvacrol (C250) and 500 mg/l carvacrol (C500). The addition of carvacrol reduced in vitro dry matter (DM), crude protein (CP) and neutral-detergent fibre (NDF) digestion. The effects induced by C250 on DM digestion at 72 h of incubation were comparable with those of M, whereas a greater reduction was obtained when carvacrol was supplemented at 500 mg/l concentration (68.9, 68.5 and 53.0 v. 76.1% for M, C250 and C500 v. C, respectively). The reduced CP potential degradability by supplements (51.2, 53.9 and 51.5 v. 72.8% for M, C250 and C500 v. C, respectively) was mainly caused by a reduction of the slowly degradable fraction. Volatile fatty acid (VFA) profiles determined after 48 h of incubation showed C250 increased butyrate and decreased acetate proportions, whereas M mainly stimulated propionate proportions, suggesting that the mechanism of action of carvacrol and M differs. C500 significantly reduced total VFA production. Carvacrol could be of great interest for its usage as a potential modulator of ruminal fermentation. Future research, including in vivo studies, in order to understand the factors that contribute to its antimicrobial activity and the selection of the optimal dose is required.