Effects of Stocking Density on Harmful Gas,Dust and Microbe Content in Broiler House

This study was conducted to evaluate the effects of stocking density on harmful gas,dust and microbe content in broiler house. A total of 1 440 21-day-age Suqin yellow-feather broilers were randomly allocated into3 groups with 3 replicates per group. These birds were assigned to 3 stocking density treatments for 8 birds per m2(low stocking density,LSD),16 birds per m2(medium stocking density,MSD)and 24 birds per m2(high stocking density,HSD)treatment,respectively. 9 pen were used with per treatment 10 m2. The experiment lasted for 21 days(from 22 to 42 days of age). The results showed that NH3 and CO2content of HSD treatment at 42 days of age were much higher than other treatment(P0.05),and dust content of LSD treatment was lower than HSD and MSD treatment(P0.05). Compared with other two treatment,the highest level of Escherichia coli in the air was in LSD treatment at 28,35 and 42 days of age(P0.05),as well as the level of Escherichia coli in the litter at 42 days of age(P0.05). The findings in this study suggested that reducing stocking density in summer could reduce the content of harmful gas and dust in flat-raising broiler house,while it was ineffective to reduce the level of microbe.