Technologically difficult, pathogenic and food risky bacterial contamination of raw milk and other materials from dairy cow herds
Hanus, O.(Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic))E-mail:oto.hanus@vuchs.cz | Frelich, J.(Jihoceska Univ., Ceske Budejovice (Czech Republic)) | Vyletelova, M.(Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic)) | Roubal, P.(MILCOM, Prague (Czech Republic)) | Vorlicek, Z.(Vyzkumny Ustav Picninarsky, Troubsko (Czech Republic)) | Jedelska, R.(Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic))
The aim of the study was to investigate the occurrence of sporulated microorganisms (SM) in raw cow's milk (M), fodders (F), and cow excrements (E) and to find out an eventual relationship between the SM concentrations in these different materials. The investigations were carried out on seven farms with a good level of hygiene during three summer (S) and winter (W) seasons. The analyses were focused on counts of thermoresistant bacteria (TRB), bacilli (TBA), Bacillus cereus (BCE), B. licheniformis (BLI), other bacilli (OBA), Streptococcus agalactiae (SAG, only in milk), and Staphylococcus aureus (SAU, only in milk). The variabilities were high: from 179% (TBA) to 315% (TRB) in F, from 178% (BLI) to 350% (TRB) in E, from 117% (TBA) to 459% (SAG) in M. The effect of the season was very low and in most of the cases not significant. Nevertheless, S increased significantly BLI in E, BCE, but decreased BLI. Significant positive correlations were between bacilli and TRB in F and E. The majority of significant relationships were in F x E within TRB, BLI, OBA, and TBA. Between 7 and 58% of the changes in E were dependent on changes in F. The occurrences of TRB and BLI in M were significantly influenced by their occurrences in E and F. The observed dependences confirm the relationships between F, E, and M.
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