Effect of litter and shed type on dust and ammonia concentration in broiler shed

Broiler chickens in Australia are traditionally reared on new litter. To increase resource utilization and improve production efficiency, industry is moving towards reusing litter in the shed for multiple batches. A study was conducted to compare the ammonia and dust production by meat chickens reared in new and reuse litter. Although Australian meat chicken industry increasingly establishing modern tunnel ventilated sheds, a vast majority of growers still using conventional sheds. Therefore, the study also investigated the dust and ammonia level in conventional and tunnel ventilated shed. To investigate the effect of shed type, ammonia concentration in ppm and particulate matter (dust) in mg/m³ of air was measured at various heights from the floor level and ages of chickens up week 7. Ammonia and dust levels were compared in new and reused litter in a separate experiment. The ammonia concentration was rapidly increasing with the age of chickens up to 3 weeks and then relatively steady up to week 5 without significant effect of shed type. The dust level was higher in conventional than tunnel shed. Overall, the dust level was increasing with the age of chickens up to week 5 and then steady or lower. The ammonia concentration in the reused litter was higher all along, whereas, dust level was higher in reused litter from week 3 and 4 but lower in week 2 and 5. Ammonia concentration always remained below the industry set limit of 25ppm.