For the broiler industry, concerns about ammonia (NH3) emission are multifaceted and include issues of live production performance, animal health, welfare, environmental impact and public perception.
Effectively managing NH3 emissions is critical to meeting foreseeable regulatory limits. Further research by industry and academia is needed to develop methods to manage and reduce NH3 emission.
Litter amendments have shown promise as a cost-effective and viable technology to reduce NH3 emission; however, the application of litter amendments has been limited to the few days before birds' placements due to health and safety concerns related to acid materials. Further research is needed to assess the feasibility and impact of frequent applications of litter amendments on NH3 volatilisation, production performance, microbial environments, bird health and food safety.
An innovative automated aerial application system has been developed to deliver and apply litter amendment products to the whole house with birds in the house. Before adoption of continuous litter amendments for commercial production conditions, assessment tests have to be conducted to document the impact of the techniques not only on NH3 emission but also on overall animal health, production performance and thus production economics.
A laboratory study was conducted, funded by US Poultry and Egg Association, to evaluate the impact of different litter amendments (PLT, zeolite and activated charcoal) and moisture levels on NH3 emission from boiler litter. PLT showed a higher emission reduction rate than zeolite, and activated charcoal did not show a capability to reduce NH3 emission at all moisture levels. Based on the small scale in the laboratory with live birds, field verification studies at a commercial site and a university research site were conducted with two different PLT application strategies. At the commercial site, three consecutive flocks of broilers were reared to an age of six weeks. PLT was applied at 21 and 35 days of age at a rate of 244 g/m2 (50 lb/1000ft2). At the university research site, five consecutive flocks were raised to an age ranging from 52 to 59 days. During each grow-out, different rates, 122, 183, 244, 305, and 366g/m2 (25, 37.5, 50, 62.5, 75 lb/1000ft2), of PLT were used weekly at the ages of 21, 28, 35, 42, and 49 days.
The results show that repeated application of PLT led to significant reduction in NH3 emissions from broiler litter. The magnitude of NH3 emission reduction increases with the application rate of PLT. The emission reduction rates of frequent PLT application during grow-out varied from 0.08 to 0.22 g-NH3/g-PLT. Frequent PLT application correlated with improved production performance and foot pad quality. Effects of PLT on aerobic bacteria counts, coliform counts, yeasts and molds are insignificant. Frequent PLT application does reduce the presence of Salmonella but not Campylobacter.
Source: US Poultry