Pregledni rad
Microorganisms in stable air as possible postsecretory milk contaminants
Kristina Matković
; Veterinarski fakultet Sveučilišta u Zagrebu, Zavod za animalnu higijenu, okoliš i etologiju , Heinzelova 55, 10000 Zagreb
Marija Vučemilo
Bara Vinković
Željko Pavičić
Srećko Matković
Sažetak
Quality and hygienic correct milk must satisfy conditions which are prescribed by Law on Raw Milk Quality (NN102/2000). If we know that freshly milked milk could contain a certain number of microorganisms originating from the stable air (so called postsecretory contamination), performed research can help in establishing microclimatic factors that can influence that kind of contamination. Research was carried out in a dairy stable, basic microclimatic parameters were analyzed as well as number of microorganisms in the stable air. Measurements were executed in the morning, at noon and in the evening, once a week, during two months. Microclimate parameters were determined by standard, attested Testo 400 device (Testo Inc., Germany) and Merck MAS-100 device (Merck KgaA, Darmstadt, Germany). Air samples were inoculated on prepared Columbia and Sabouraud agar (Biolife, Milan, Italy). After incubation and counting, the most common colonies were reinoculated on selective medium and identified by microbiological procedures. Obtained values were analyzed by statistical program Statistica. Mean values of total bacterial count in stable air were between 8.81 x 104 CFU/m3 at noon up to 1.26 x 105 CFU/m3 in the evening, and mean values of total moulds count in stable air were between 5.23 x 104 CFU/m3 at noon up to 8.35 x 104 CFU/m3 in the morning. Ten bacterial genus’s were identified. The most common bacteria in stable air were gram-positive bacteria, specially Staphylococcus i Streptococcus genera. Nine mould genera were isolated, predominated by the genera Aspergillus, Penicillium and yeasts. By Wilcoxon matched pair test at a level of statistical significance of p<0.05 was demonstrated that air temperature, relative humidity and air flow velocity directly influence on total number of microorganisms in stable air. Number and species of identified microorganisms in stable air could have influence on hygiene quality of fresh milk. Therefore, by regularly conduction of zoohygienic measures, regulatory udder hygiene before and after milking as well as milking equipment hygiene have to be conducted, to prevent postsecretory milk contamination.
Ključne riječi
microorganisms; air; milk; pollution
Hrčak ID:
8413
URI
Datum izdavanja:
23.12.2006.
Posjeta: 2.970 *