Concentration of harmful gases in poultry and pig houses

A common chicken broilers rearing house and fattening pig barn were monitored for harmful gases concentration (NH3, CO2, NO2 and CH4). In chickens the concentrations of NH3 rose during fattening periods in all seasons of the year (from 0.23 to 10.77 mg.m(-3)). They varied depending on the ventilation rate and were influenced by litter temperature. The daily mean concentrations of CO2 were decreasing towards the end of the fattening period and were influenced by heating at the beginning and by birds breathing at the end of fattening periods. Mean daily concentrations of N2O ranged from 0.92 to 8.24 mg.m(-3) and CH4 from 46.59 to 134.12 mg.m(-3). In the pig house the NH3 concentrations varied from 2.64 to 22.9 mg.m(-3), but not simultaneously to the growth of body weight as in chickens. They also varied depending on ventilation rate, but differences in that parameter between the colder and warmer periods were not found sinificant. The mean daily production of CO2 ranged from 975.36 to 9948.78 mg.m(-3), N2O from 1.08 to 6.39, and CH4 from 33.51 to 189.63, without any significant differences between periods and with no relation to age and weight of animals. Significant positive correlations in chicken broilers were found between the production of ammonia and litter temperature and in cold periods also with ventilation rate. In fattening pigs higher correlations related to methane production were found only.