Comparative life cycle assessment of amino acid use in pig, broiler and egg production.
In 2015, Evonik reported a comparative life cycle assessment (LCA) of methionine, lysine, threonine, tryptophan and valine in broiler and pig production (Haasken 2015). As part of the process, TÜV Rheinland LGA Products GmbH conducted a critical review according to ISO 14040 and ISO 14044 (ISO 2006; ISO 2009). Like this previous study, the 2021 LCA analyzes the environmental impact related to feed with low protein levels and balanced amino acid profiles, and compares it to the environmental impact of feed customary in the respective market as a benchmark.
However, the 2015 study still compared the low protein feed to a feed without any amino acid supplementation. Since then a basic level of amino acid supplementation has become customary and the feed composition of the benchmark in the present study has been adjusted accordingly. In addition, in various regions the analyzed “best practice” low protein diets now include more than the five above mentioned amino acids.
All in all, the scope of the study has shifted, and the present study focuses on the environmental impacts of changing feed composition towards optimized diets with balanced amino acid profiles and with low crude protein content without negative impact on animal welfare. Thus, the technology to optimize feed with amino acids is at the center of the study instead of the assessment of single products or processes.
The system boundaries follow the principle “from cradle to grave”, i.e. they start from production of feed raw materials and continue with animal farming and emissions from manure treatment. Further processing of animal products (that is, especially slaughtering and meat processing) are not part of the study, because feed composition has no relevant impact on them. Different feed compositions are considered for Europe, North America, South America, North Asia and (only for pigs and broilers) South Asia, respectively.
Evonik offers its customers extensive services regarding analysis of feed’s nutritional characteristics as well as advice on creating feed mixes with low protein levels, which are only feasible without threatening animal welfare due to balanced amino acid supplementation. This expertise and extensive market knowledge allowed experts from Evonik to assess precise and realistic scenarios for the different markets and to model two feed mix options for each region and animal species under investigation:
1.“Evonik solution”: Feed mix with a balanced amino acid profile based on Evonik’s best recommendations, representing best practice for diets with low protein levels.
2. Benchmark”: Feed mix with an amino acid supplementation customary in the regional market.
Since nutritional requirements and feed composition change over the course of animals’ lives, an average feed composition of the various phases was calculated considering the feed intake during each phase of life (with two different phases considered for pigs, three phases for broilers and the egg-laying phase for laying hens).
The following impact categories and methodologies were included in the evaluation:
- Global Warming Potential (GWP) excl. biogenic carbon and including Landuse Change (LUC), kg CO2e
- Acidification Potential (AP), kg SO2e
- Eutrophication Potential (EP), kg PO4e
- Blue Water Consumption, kg water
- Agricultural Land Occupation, m² * a
- Respiratory inorganics, disease incidences
The results for GWP of broilers, pigs and eggs are dominated by the LUC associated with soy products and thus differ strongly depending on soy origin. Since the “Evonik solution” feed mixes include lower amounts of soy products and instead higher amounts of amino acids than the “Benchmark” feed mixes, GWP for the “Evonik solution” is 3 to 21 percent lower for all three functional units in all regions, except for North America.
Because soy products fed in North America are assumed to cause nearly zero LUC and amino acids require more raw materials and energy for production than many agricultural ingredients, the additional amino acids can have a higher specific GWP than the replaced feed materials. As a result, in North America the GWP of the “Evonik solution” is 3 percent lower than the “Benchmark” for eggs, similar to the “Benchmark” for pigs (0 percent difference) and 8 percent higher than the “Benchmark” for broilers.
While the AP of feed is very similar for the “Evonik solution” and “Benchmark”, the lower nitrogen content of excretions and lower ammonia emissions during manure storage and application lead to the “Evonik solution” having a 5 to 16 percent lower AP for all regions and functional units.
The EP of the “Evonik solution” is 4 to 19 percent lower than the EP of the “Benchmark” for all regions and functional units. A share of this decrease is caused by lower EP of feed, whereas a bigger share of the decrease is caused by decreased nitrogen content of excretions and thus lower ammonia and nitrous oxide emissions such like N2O during manure storage and application.
Blue water consumption is dominated by the impact of feed production whereas direct water consumption of animals during farming plays only a minor role. The blue water consumption of the “Evonik solution” is similar or lower (0 to -12 percent) than the “Benchmark” in Europe and North America and is similar or higher (+1 to +18 percent) than the “Benchmark” in the other regions. This strong regional deviation results from the specific blue water consumption of the region-specific soy products, corn and wheat.
Land occupation is caused nearly exclusively by feed production, except for litter production for broiler housing. The land occupation related to the “Evonik solution” is similar or lower (0 to -13 percent) than the land occupation of the “Benchmark” for all regions and functional units. Similar to blue water consumption, these changes are driven by the specific land occupation of various feed ingredients whose amounts differ in the “Evonik solution” and “Benchmark” (among them amino acids, soy products, corn, wheat and animal products like meat and bone meal).
The respiratory inorganics related to the “Evonik solution” are 4 to 32 percent lower than the respiratory inorganics of the “Benchmark” for all regions and functional units. In most cases, the “Evonik solution” has no significantly different impact from feed production and the whole reduction of respiratory inorganics is caused by lower impacts from manure storage and application. The reduction of respiratory inorganics from manure storage and application is caused by decreased nitrogen content of excretions and thus lower ammonia emissions.
Using feed with low protein levels and balanced amino acid profiles can strongly influence the environmental impact of animal products such as pigs, broilers and eggs. The reduced protein levels lead to reduced nitrogen content of excretions, which in turn leads to reduced air and water nitrogen pollution. Reduced N2O and thus reduced GWP of manure treatment only have a small impact on overall GWP of pigs, broilers and eggs compared to the GWP of feed production. However, as the main benefit, the decreased air and water nitrogen pollution leads to the reduction of AP, EP and respiratory inorganics.
Evonik solutions (including nutritional services and consultancy) enable increased sustainability performance of livestock operations such as pig, poultry and egg production compared to the market reference without compromising animal welfare and:
- lead to significant mitigation options for climate change and nitrogen-based emissions, which contribute to acidification potential (AP), eutrophication potential (EP) and respiratory inorganics,
- enable the reduction of ecological impacts when further reducing the crude protein in feed based on the future availability of other limiting essential amino acids.
Low crude protein diets according to the advanced feed formulations of Evonik Animal Nutrition services and consultancy:
- enable increased usage of regionally produced feed materials by replacing imported oil seeds,
- support deforestation-free supply chains.