A17 An increase in bedding material in pig housing
Measure | Sector | Net Effect | Impact | Reliability | Tech. rqmt. | |||||
---|---|---|---|---|---|---|---|---|---|---|
NH3 | N2O | NOx | Nr to water | N2 | ||||||
A17 An increase in bedding material in pig housing | Sector Livestock farming | Net Effect 3 | NH3 3 | N2O 3 | NO2 | Nr to water | N2 | Reliability Robust | Tech. rqmts. Low |
Overview
Proper nitrogen management in pig housing is crucial for mitigating ammonia and nitrous oxide emissions, both of which are potent greenhouse gases and contribute to environmental pollution and climate change. A promising approach to address this issue is through the use of bedding materials that efficiently absorb urine (Figure 1). When pigs urinate, bedding materials such as straw or sawdust capture and immobilise nitrogen from the urine, preventing its immediate release as ammonia (Gilhespy et al., 2009; Bittman et al., 2014). By reducing ammonia emissions, this bedding strategy not only improves air quality and minimises the negative impact on human health but also helps retain nitrogen within the system, potentially benefiting soil nutrient cycling and crop productivity. This measure is regarded as a dependable and low-tech approach to reduce nitrogen emissions and can positively interact with animal welfare measures.
Figure 1. Loose-housing of sows in pens with deep straw bedding and individual feeding stalls. Photography by Linda Engblom.
Measure Efficiency
The choice of bedding material in animal housing can significantly influence emissions of ammonia, nitrous oxide, nitrogen oxides, and dinitrogen. Among the characteristics of bedding materials, their physical properties, such as urine absorbance capacity and bulk density, appear to have a greater impact on ammonia emissions from dairy barn floors than their chemical properties, such as pH, cation exchange capacity, and carbon to nitrogen ratio. Nonetheless, more comprehensive investigations are required to understand the bedding material's effect on emissions in specific systems while considering the entire manure management process.
Gilhespy et al., (2009) assessed the impact of increasing straw usage on ammonia emissions in buildings housing cattle or pigs. The introduction of additional straw into these facilities has the potential to decrease ammonia emissions through two mechanisms: first, by reducing the airflow over urine-soiled surfaces, and second, by immobilising ammonium-nitrogen. The researchers applied extra straw in increments of up to 100%, either broadcast across the entire floor or specifically targeted to areas with higher excreta deposition. Results revealed that an increase of 33% straw, broadcast over the entire floor, led to a 50% reduction in ammonia emissions from cattle. However, further additions of straw did not result in significant additional reductions. For pigs, only a broadcast addition of 100% more straw led to a modest reduction of approximately 20% in ammonia emissions. Targeted use of an additional 33% straw reduced cattle emissions by 22% compared to broadcasting the same amount of straw, but additional targeted straw use did not yield further reductions. When the straw was targeted in the pig buildings there was no benefit from using additional straw there was no evident benefit from using additional straw. Consequently, optimal results may be achieved with an addition of 33% extra straw, specifically targeted to soiled areas for cattle, whereas 100% extra straw broadcast across the whole floor is more effective for pigs.
How to implement
Bedding material helps to absorb and retain nitrogenous waste, preventing it from volatilising into the atmosphere as ammonia and nitrous oxides. To implement his measure may involve the following steps:
- Assess the current nitrogen management and emissions: Before making any changes, conduct a thorough assessment of the current situation. Measure and record the emissions of ammonia and nitrous oxides from the pig housing. Understand the existing bedding material usage and its effectiveness in nitrogen retention.
- Select suitable bedding material: Choose bedding materials that have high nitrogen absorption capacity and are readily available in the region. Common options include straw, wood shavings, sawdust, rice hulls, or recycled paper (Ahn et al., 2016b; a; Yajima et al., 2017). Each material has its advantages and disadvantages, so choose the one that best suits the specific circumstances.
- Calculate the optimal bedding material quantity: Determine the ideal amount of bedding material needed based on the number of pigs, their waste production rate, and the desired nitrogen retention capacity. The right amount of bedding material is crucial to ensure effective nitrogen management.
- Properly maintain the bedding: Regularly clean and maintain the bedding to avoid buildup and saturation. A buildup of waste can reduce the effectiveness of the bedding in retaining nitrogen and increase the risk of ammonia emissions.
- Provide sufficient drainage and ventilation: Proper drainage systems and ventilation are essential to manage moisture levels and prevent anaerobic conditions that can lead to increased nitrogen losses through volatilisation.
- Monitor and adjust the bedding material: Continuously monitor ammonia and nitrous oxide emissions, as well as the condition of the bedding material. Make adjustments as needed to optimise nitrogen management and minimise emissions.
- Consider composting: Instead of removing used bedding material directly, consider composting it along with manure and other organic wastes. Composting can further reduce nitrogen losses while producing a valuable nutrient-rich fertiliser.
- Explore other sustainable practices: Increasing bedding material is just one aspect of sustainable nitrogen management. Look into other practices like diet modification, manure treatment, and housing design improvements to complement the bedding material strategy and enhance overall sustainability.
- Educate and involve stakeholders: Ensure that all personnel involved in pig management are educated about the importance of sustainable nitrogen management and the role of bedding material. Encourage active participation in the implementation and maintenance of the new practices.
By following these steps and continuously monitoring and adapting the approach, an increase in bedding material in pig housing to improve sustainable nitrogen management and reduce ammonia and nitrous oxide emissions can be successfully implemented. This will not only benefit the environment but also enhance the overall health and well-being of the pigs and the farm's economic performance.
Benefits
Increasing bedding material in pig housing to improve sustainable nitrogen management can bring about several significant benefits:
Overall, increasing bedding material in pig housing as part of a comprehensive sustainable nitrogen management strategy not only benefits the environment and surrounding communities but also improves animal welfare and economic viability for the farm. It's a win-win approach that supports both the farm's long-term viability and the health of the planet.
Costs
Captial Costs
Captial costs will vary depending on the scale of the operation and local factors, however, some potential capital costs to consider include:
It's important to remember that while there might be initial capital costs, implementing sustainable nitrogen management practices can have long-term benefits, including reduced input costs, improved animal health, and better environmental stewardship. Additionally, some investments, like composting facilities or better ventilation, can lead to cost savings and improved overall efficiency in the long run. Additionally, government grants, subsidies, or financial assistance programs to support sustainable farming practices and help offset such capital costs should be explored.
Operational Costs
Potential operational costs to consider include the following:
As with capital costs, conducting a cost-benefit analysis specific to the farm's circumstances will provide valuable insights into the financial implications of implementing these sustainable practices.
Risks
While increasing bedding material in pig housing to improve sustainable nitrogen management has several benefits, the following potential risks and challenges. Should be considered:
To address these risks, it's crucial to carefully plan and manage the increase in bedding material. Proper storage, handling, and maintenance practices are essential to ensure its effectiveness and avoid negative impacts. Farm managers should also consider factors such as climate, farm size, and available resources when deciding on the best bedding material and the appropriate quantity to use. Regular monitoring and data collection can help identify any issues early on and allow for timely adjustments to the bedding management strategy.
References
Ahn, G.C., S.S. Jang, H.J. Kwak, S.R. Lee, Y.K. Oh, et al. 2016a. Characteristics of Rice Hulls, Sawdust, Wood Shavings and Mixture of Sawdust and Wood Shavings, and Their Usefulness According to the Pen Location for Hanwoo Cattle. Asian-Australasian J. Anim. Sci. 29(4): 599–605. doi: 10.5713/ajas.15.0863.
Ahn, G.C., S.S. Jang, K.Y. Lee, W.S. Kwak, Y.K. Oh, et al. 2016b. Characteristics of Sawdust and Cocopeat Beddings, and Their Usefulness According to the Fan and Pen Location for Rearing Hanwoo Cattle. Asian-Australasian J. Anim. Sci. 29(3): 444–54. doi: 10.5713/ajas.15.0672.
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.
Gilhespy, S.L., J. Webb, D.R. Chadwick, T.H. Misselbrook, R. Kay, et al. 2009. Will additional straw bedding in buildings housing cattle and pigs reduce ammonia emissions? Biosyst. Eng. 102(2): 180–189. doi: 10.1016/j.biosystemseng.2008.10.005.
Yajima, A., H. Owada, S. Kobayashi, N. Komatsu, K. Takehara, et al. 2017. Cacao bean husk: an applicable bedding material in dairy free-stall barns. Asian-Australasian J. Anim. Sci. 30(7): 1048–1053. doi: 10.5713/ajas.16.0877.
Authors
Will Brownlie
UK Centre for Ecology and Hydrology, Scotland