Effects Of Frequent Application Of Litter Amendments In Broiler Houses During Grow-Out On Animal Health, Production And Environment

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 volatilization, 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.

The objectives of this study were:

1) to evaluate/screen the efficacy of litter amendments (sodium bisulfate (PLT®), biochar and zeolite) with continuous application at different rates on reduction of ammonia emission;

2) to determine continuous application requirements of the litter amendments that prove promising from evaluation tests, without compromising production performance and health of broilers raised in climate controlled chambers by simulating field conditions; and

3) to conduct field verification tests and economic analyses on sodium bisulfate regarding production performance, litter quality, and air emission reduction efficacy over an extended period to address the seasonal effects.

A laboratory study was conducted 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.