A18 Remove cattle slurry from under slats to outside store
Last Update:
| Measure | Sector | Net Effect | Impact | Reliability | Tech. rqmt. | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| NH3 | N2O | NOx | Nr to water | N2 | ||||||
A18 Remove cattle slurry from under slats to outside store  | Sector Livestock farming | Net Effect 2 | NH3 2 | N2O  | NO2 | Nr to water | N2 | Reliability Robust | Tech. rqmts. Low |
Overview
Regular removal of cattle slurry from under the slats in an animal house (Figure 1) with vacuum or gravity removal systems or by flushing systems at least twice a week; to a covered outside store can lead to significant improvements in nitrogen management (Aarnink and Elzing, 1998; Bittman et al., 2014). Below the fully-slatted or part-slatted floor, outlets are strategically positioned every ~10m2 and connected to a sewerage system. In a vacuum removal system, a valve in the main slurry pipe is opened, creating a slight vacuum that facilitates the slurry's expulsion. The frequency of emptying the pit varies, occurring once or twice a week, depending on the pit's capacity.
This practice is a reliable measure to reduce ammonia emissions by minimizing the emitting surface and lowering the slurry storage temperature (Bittman et al., 2014). By promptly transferring the slurry to an outside store, the accumulation of nitrogen-rich residues is minimised, mitigating the release of ammonia into the atmosphere. Additionally, this method has the added benefit of reducing methane emissions since manure is stored outside under cooler conditions. This approach contributes to more efficient nutrient management, improved environmental sustainability, and better air quality, making it a valuable strategy for optimising nitrogen management in livestock farming.
Figure 1. A precast concrete slatted systems for housing cattle. Picture source: https://mjharrisonsupplies.co.uk/agricultural/livestock-suspended-flooring-systems/
Measure Efficiency
The percentage reduction in ammonia emissions achieved by the regular removal of slurry from under the slats in cattle housing to a covered outside store can vary depending on several factors. These factors include the specific management practices, the size of the animal facility, the number of animals, and the initial level of ammonia emissions.
Bittman et al., (2014) suggest ammonia emission can be reduced by 25% by reduction of emitting surface area through frequent and complete vacuum-assisted drainage of slurry from the floor of the pit, compared to fully slatted floor with a deep manure pit underneath and mechanical ventilation. However, it's important to note that individual results may vary depending on the specific conditions of each farm and the overall nitrogen management practices implemented.
While the percentage reduction in ammonia emissions can be significant, the actual effectiveness of this measure in a specific setting will also depend on other nitrogen management strategies in place. A comprehensive approach that includes proper ventilation, waste management, and nutrient utilisation will further enhance the overall reduction of ammonia emissions in livestock farming.
How to implement
Implementing regular removal of cattle slurry from under the slats in an animal house to a covered outside store can be achieved through the following steps:
- Design and Infrastructure: Ensure the animal house is designed with appropriate infrastructure to facilitate slurry removal. Gravity removal systems, vacuum systems, or flushing systems should be properly installed and maintained.
- Establish a Cleaning Schedule: Develop a cleaning schedule that includes vacuuming, flushing, or gravity removal of cattle slurry at least twice a week. Consistency in the schedule is crucial to maintain cleanliness and reduce ammonia emissions effectively.
- Train Personnel: Properly train farm personnel responsible for slurry removal to ensure they follow the established cleaning schedule and handle the equipment safely and efficiently.
- Use Covered Outside Store: Set up a covered outside store to store the removed cattle slurry. A covered store helps prevent excessive evaporation, reducing ammonia emissions and maintaining better nutrient content in the slurry.
- Ensure Proper Ventilation: The covered outside store should be designed with proper ventilation to minimise gas buildup and maintain good air quality.
- Regular Maintenance: Regularly inspect and maintain the slurry removal systems and outside store to ensure they function optimally and minimise any potential leaks or inefficiencies.
- Monitor Ammonia Emissions: Periodically monitor ammonia levels in the animal house and outside store to assess the effectiveness of the slurry removal process and make any necessary adjustments.
- Safety Considerations: Implement safety protocols for slurry removal, storage, and handling to protect both farm personnel and the environment.
- Compliance with Regulations: Ensure that the slurry removal and storage practices comply with local regulations and environmental guidelines to avoid any legal issues.
By implementing these measures, an operation can efficiently remove cattle slurry from the animal house and store it outside in a covered store, leading to reduced ammonia emissions and improved nitrogen management in cattle farming. Regular cleaning and proper slurry management contribute to better animal health, reduced environmental impacts, and enhanced overall farm sustainability.
Benefits
The regular removal of cattle slurry to a covered outside store come with several benefits that positively impact farm operations and the environment:
Overall, the operational costs associated with regular slurry removal to a covered outside store are offset by the numerous benefits it brings. The practice contributes to better farm efficiency, animal health, environmental sustainability, and community relations, making it a valuable investment for modern and responsible cattle farming.
Costs
Captial Costs
The capital costs of implementing regular removal of slurry from under the slats in an animal house with vacuum or gravity removal systems or by flushing systems to a covered outside store can vary depending on various factors. Some of the potential capital costs include:
It's important to conduct a thorough cost analysis, including obtaining quotes from suppliers and contractors, to estimate the precise capital investment required for implementing the regular removal of cattle slurry to a covered outside store. Additionally, some regions may offer financial incentives or grants for adopting sustainable agricultural practices, which could help offset some of the capital costs.
Operational Costs
The operational costs of regular removal of cattle slurry from under the slats in an animal house with vacuum or gravity removal systems or by flushing systems to a covered outside store can include:
It's essential to consider these operational costs along with the benefits of efficient slurry removal and nitrogen management. Proper planning, optimisation of systems, and efficient use of resources can help manage the operational expenses and make the regular removal of cattle slurry to a covered outside store a cost-effective and environmentally sustainable practice.
Risks
While regular removal of cattle slurry to a covered outside store offers significant benefits, there are also some potential risks and challenges to consider:
To mitigate these risks, it is essential to implement proper training for farm personnel, maintain equipment regularly, adhere to safety protocols, and develop a comprehensive slurry management plan. By addressing these potential risks, farmers can maximise the benefits of regular slurry removal while minimising potential negative impacts on the environment and farm operations.
References
Aarnink, A.J.A., and A. Elzing. 1998. Dynamic model for ammonia volatilization in housing with partially slatted floors, for fattening pigs. Livest. Prod. Sci. 53(2): 159–169.
Bittman, S., M. Dedina, C.M. Howard, O. Oenema, and M.A. Sutton, editors. 2014. Options for Ammonia Mitigation: Guidance from the UNECE Task Force on Reactive Nitrogen. Centre for Ecology and Hydrology, Edinburgh, UK.
Authors
Will Brownlie
UK Centre for Ecology and Hydrology, Scotland