Studies on the concentrations of particulate matter and ammonia gas from three laying hen rearing systems during the summer season.

This study aimed to measure the concentrations of particulate matter (PM, PM) and ammonia gas (NH) from different types of laying hen houses during summer. The treatment groups included conventional cage, floor pens, and aviary system, with tunnel ventilation system applied to all poultry houses. The PM concentration was highest in the aviary system from 10:00 h to 18:30 h, whereas in the cage, it remained high after 18:30 h until 7:30 h the next day. The cage showed high levels of PM from 18:30 h to 7:30 h the next day. The correlation between the three breeding systems showed an < 0.2. The mean daily concentrations of PM, PM, and NH were highest in the cage, among all the poultry houses. On comparing the two welfare breeding systems (floor pens and aviary system), particulate matter concentrations were higher in the floor pens, while the aviary system had higher level of NH. However, no significant differences were observed between the concentrations of PM, PM, and NH between the three laying hen houses in summer. This study provides basic data for improving the rearing environment in the three different types of poultry housing systems.