Microbial air pollution caused by intensive broiler chicken breeding

Abstract

Studies on the degree of microbial atmospheric pollution caused by industrial broiler breeding were carried out. The experiments were performed with broiler chickens bred on litter that was not changed, at a density of 20 chickens m−2 in uniform buildings each possessing a total area of 960 m2. A gradual increase of the microbial numbers in the indoor air was observed as the birds aged (1.25×103 to 1.68×105 m−3 air). The ageing of the birds was also accompanied by a more massive emission of microorganisms into the environment (2.86×109 to 3.05×1013 emitted in the air over 24 h per building). These studies, concerning the problems of microbial pollution caused by the industrial breeding of farm animals, indicate that the microorganisms could be dispersed by air flow for up to 3000 m from the production buildings.

The variability of bacterial aerosol in poultry houses depending on selected factors

“…In the facilities with older flocks (other buildings), the level of microorganisms was higher by several orders of magnitude. The same tendency was reported by other authors [11,29,30]. The mean concentration of Gram-negative bacteria obtained in our study (9.38×10 5 cfu/m 3 ) exceeded the levels of this group of bacteria presented by several authors.…”

“…Besides the basic assessment of quantitative and qualitative bacterial aerosol present in the air of poultry houses, the authors also studied the influence of several aspects of hen breeding on concentrations of these microorganisms in the air of poultry premises. Several authors determined the levels of airborne bacteria depending on age of hens or broilers and housing density of birds [5,11,12,23,29,30]. Furthermore, Nimmermark et al [2], Saleh et al [6] and Kirychuk et al [17] showed that poultry production system (floor housing system with litter, house with cages) was also important.…”

The aerobiology of the environment around mechanically ventilated broiler sheds

“…At extended distances (for example beyond 500 m) and outside the close vicinity of the farm, higher levels of total bacteria can be attributed collectively to various other sources. Baykov and Stoyanov (1999) attributed total bacterial levels at distances as far as up to 3000 m from the intensive poultry production environment. It is possible that other sources could have been a contributory factor.…”

“…Few studies have dealt with quantifying the levels of microbes in aerosols in and around mechanically ventilated poultry environments. Birds grown on litter (sawdust or straw with a litter thickness of 8-10 cm) under intensive broiler production in mechanically ventilated sheds yielded total bacterial counts in the air that depended on bird age (Baykov and Stoyanov 1999). These bacterial counts ranged from 1AE25 · 10 5 m )3 at the beginning of the trial to 1AE68 · 10 7 m )3 at the end of the trial (day 56) (Baykov and Stoyanov 1999).…”

“…Birds grown on litter (sawdust or straw with a litter thickness of 8-10 cm) under intensive broiler production in mechanically ventilated sheds yielded total bacterial counts in the air that depended on bird age (Baykov and Stoyanov 1999). These bacterial counts ranged from 1AE25 · 10 5 m )3 at the beginning of the trial to 1AE68 · 10 7 m )3 at the end of the trial (day 56) (Baykov and Stoyanov 1999). Another study (with more or less similar conditions to the previous study) also showed an increase in levels with the increase in bird age and body weight recording concentrations of bacteria within the similar range in air inside the shed (1AE7 · 10 4 to 2AE2 · 10 5 CFU m )3 ) (Vučemilo et al 2007).…”