Effects of laying hens housing system on eggs microbial contamination

Abstract

Microorganisms can contaminate eggs at many stages of production, handling, preparation, and consumption. The aim of our study was the microbiological quality of the internal contents of eggs from different layer housing systems. Total bacteria, coliforms, and Salmonella spp. were isolated and identified by mass spectrometry. Total bacterial counts were isolated on Plate count agar for 48 hours at 30 °C, coliforms on Violet red bile lactose agar for 24 hours at 37 °C and Salmonella spp. on Xylose lysine deoxycholate agar for 24 hours at 37 °C. The lowest total bacterial counts were found in the cage-rearing system and the highest in the aviary-rearing system for hens housing. The number of microorganisms was evaluated on days 0. and 21. Twenty species, eighteen genera, and sixteen families were isolated from enriched cages in 0 days, while three families, three genera, and five species were isolated in 21 days, according to egg content samples. Thirteen families, sixteen genera, and twenty species were isolated from egg contents samples in the deep litter on day zero and day twenty-one, respectively, by third families, fourth genera, and seventh species. Nine families, twenty genera, and fifteen species were identified in aviaries using egg content samples on day 0, and three families, three genera, and five species on day 21. Ralstonia pickettii was the most isolated species among all samples.