Wednesday, February 21, 2024

The role of feed-grade amino acids in the bioeconomy: Contribution from production activities and use in animal feed

Estimated reading time: 15 minutes

  • Bioeconomy will make for a better future. Policymakers recognise this with the inclusion in the EU Bioeconomy Strategy.
  • For the assessment of the status and the development of the bioeconomy, a monitoring system is needed. One of the EU’s 2018 Bioeconomy Strategy update actions foresees the development of an EU-wide, international coherent monitoring system to track economic, social and environmental progress towards a circular and sustainable bioeconomy.
  • The order of the introduction of amino acids in animal feed reflects the typical discrepancy between the requirements for amino acids by species and their actual presence in feed.
  • Positive effects from the use of free amino acids in feed come from both bio-based and fossil-based free amino acids. The main contribution comes from the use of the first limiting amino acid.
  • Farmers in the EU use feed-grade amino acids mainly by using compound/mineral feed. Therefore, the producer’s demand for compound/mineral feed for feed-grade amino acids could be seen as a good proxy for the total demand of feed-grade amino acids.

A sustainable and circular bioeconomy is an option for a better future (Sturm and Banse, 2021; Chavarria et al., 2020; Fritsche et al., 2020). Policymakers in the European Union (EU) recognise this and confirm the importance of the contribution a sustainable and circular bioeconomy can make to achieving the sustainable development goals (SDGs) as well as the Paris Agreement by the EU’s 2018 Bioeconomy Strategy update.

With the European Green Deal, important steps of integration of bioeconomy in other EU policies related to biodiversity, circularity, climate change, food systems, forest protection and restoration, and renewable energy are underway.

For the assessment of the status and the development of the bioeconomy, a monitoring system is needed. One of the EU’s 2018 Bioeconomy Strategy update actions foresees the development of an EU-wide, international coherent monitoring system to track economic, social and environmental progress towards a circular and sustainable bioeconomy.

The European Commission (EC) Joint Research Centre (JRC) is leading this action, in collaboration with several Commission Services and stakeholders. The approach for the EU bioeconomy monitoring framework was developed (Kilsedar
et al., 2021; Robert et al., 2020) and the first release of the EU Bioeconomy Monitoring System 1 was launched in November 2020; further improvements should follow.

At the same time, some bioeconomy monitoring activities are already taking place at the level of EU member states and there are even initiatives to set up a national bioeconomy monitoring system (Lier et al., 2018).

Thus, in 2016, the Federal Government of Germany initiated the development of a comprehensive bioeconomy monitoring system. Research projects based on this initiative resulted in a conceptual proposal for setting up a monitoring system in Germany and generated the first results (Banse et al., 2021; Iost et al., 2020; Bringezu et al., 2020). Furthermore, ongoing bioeconomy research projects result in additional proposals and recommendations concerning establishing a bioeconomy monitoring system (Kardung et al., 2021).

Despite some differences in the proposed approaches for setting up a monitoring system and indicators used to track the developments in the bioeconomy, one is common for all of them – the need for a sound database.

To test and validate proposed methodologies (Piotrowski et al., 2019) case studies were conducted. One of the conducted case studies focusses on the dynamics on the markets for feed-grade amino acids (Sturm et al., 2021). Amino acids contribute to a bioeconomy through associated producing activities as well as through their use in different applications.

Relevant producing activities are related to the production of bio-based amino acids mainly through the fermentation process, although other approaches to produce amino acids from bio-based feedstocks are also gaining attention (Deng et al., 2018; Tian et al., 2021; Song et al., 2020; Hirasawa and Shimizu, 2016).

Contribution to the GDP, value-added or employment associated with these activities could be directly assigned to the bioeconomy. Besides direct contribution to the bioeconomy through production activities, amino acids also contribute significantly to the bioeconomy through their use.

The areas of application of free amino acids include the use in animal feed, food and dietary supplements, pharmaceuticals, cosmetics and as precursors for bio-based plastics and other chemicals. However, the use in animal feed is currently the most important application category and we focus on this by looking into feed-grade amino acids.

Introduction of amino acids

The industrial application of amino acids for feed has an almost 60-year history (Toride, 2004). First, in the late 1950s and 1960s, methionine (Met), produced by chemical synthesis, began to be used in poultry feed. Production of lysine (Lys) by a fermentation process was started in the 1960s. In the late 1980s, threonine (Thr) and tryptophan (Trp) also produced by the fermentation process were introduced.

The order of the introduction of amino acids in animal feed reflects the typical discrepancy between the requirements for amino acids by species and their actual presence in feed. The first amino acid, the absence of which interrupts protein synthesis of the other amino acids, is called the ‘first limiting’ amino acid. Table 1 shows, based on Toride (2004), the orders of limiting amino acids in pig and broiler feeds, composed of maize/wheat and soya bean meals.

With feed formulation becoming increasingly advanced, further amino acids such as valine (Val), isoleucine (Ile), leucine (Leu), arginine (Arg), histidine (His) and cystine (Cys) are considered to be used in feed. Besides the introduction of new free amino acids in feed for monogastric animals (poultry and swine), the introduction of amino acids in feed for ruminants (in particular dairy cows) takes place. Coated Met and Lys, which can escape microbial degradation in the rumen, are already available on the market (Sturm et al., 2021).

Feed additives in general and amino acids specifically are usually not used on farms as such, and the feed additive value chain is composed of multiple actors, as described based on FAO (FAO, 2019) in Figure 1. It can be implied that the use of amino acids for animal feed could be covered by producers of compound feed, as the vast majority of amino acids are supplied to livestock producers through this channel.

Assessment tools

Generally, LCA analysis is an appropriate tool to assess the contribution of amino acids to the bioeconomy through their use in animal feed. The establishment of an appropriate database and methodologies, however, is very demanding and quite challenging.

The Global Feed LCA Institute (GFLI) is developing an LCA database and tool, which aims together with the underlying UN FAO LEAP-based methodology to be the reference for assessing and benchmarking feed industry impacts and improvement in LCA calculations. The GFLI database consists of the LCA of raw materials from various regions in the world. Currently, this LCA database does not incorporate free amino acids used in animal feed, but it might be the case in the future.

Some firms, i.e. producers of feed additives such as Evonik and BASF, have already developed dedicated tools that make use of LCA and should enable the assessment of the environmental impact of both feed and the final animal protein product (Sturm et al., 2021). These tools are also supposed to be able to assess what effects feed additives such as amino acids introduced into animal feed have.

Effect of amino acids

Positive effects from the use of free amino acids in feed come from both bio-based and fossil-based free amino acids. The main contribution comes from the use of the first limiting amino acid. Therefore, in the case of pigs, the main effect comes from bio-based free amino acids (mainly Lys), while in the case of poultry, the main contribution is associated with the use of fossil-based free amino acids (Met).

At a certain point, when the use of a second and subsequent limiting amino acid is required, the additional positive effect is attributed to the use of two or more free amino acids. The effect from further use of an additional unit of the first limiting amino acid decreases in favour of the second and subsequent limiting amino acids.

Thus, due to the cross-cutting effects, the cumulative impact is not equivalent to the sum of effects from the use of each free amino acid. This makes the analysis even more challenging, without even taking into consideration that positive effects could also be a result of interaction from the use of free amino acids with other feed components, for example other feed additives.

The assessment of the impact of the use of free amino acids in the feed will hopefully be more profound in the future due to the expected progress in LCAs of feed components, as well as due to the development of dedicated tools. The amount of literature showing the positive environmental effects from the use of amino acids in animal feed are growing (Selle et al., 2020; Kebreab et al., 2016; Reckmann et al., 2016).

However, it could hardly be expected that the quantification of the absolute impact from the use of free amino acids in the feed will be possible. Most of the studies conduct comparative life cycle assessments and analyse the performance of different diets, without or with a certain amount of free amino acids, and cannot be used to generalise which environmental effects the total amount of amino acids used in feed has in the EU.

Results

Contribution to the bioeconomy through the use in animal feed

Farmers in the EU use feed-grade amino acids mainly by using compound/mineral feed. Therefore, the producer’s demand for compound/mineral feed for feed-grade amino acids could be seen as a good proxy for the total demand of feed-grade amino acids.

The EU producers of compound feed use the free amino acids directly or in the form of ‘premixtures’ (mixtures of feed additives or mixtures of one or more feed additives with feed materials or water used as carriers). The premixes used in the formulation of feed in the EU are mainly produced in the EU; hardly any import of premixes from non-EU countries takes place. However, EU producers of premixtures export their products to other EU countries as well as to non-EU countries.

The use of amino acids in animal feed is driven by the level of feed efficiency that should be achieved and the quantity of animals. In the EU, conventional livestock farming shows a high level of feed efficiency, which goes along with a relatively intensive use of amino acids in feed. The demand for individual amino acids depends on the number of individual species as a requirement for supplemented amino acids in feed, and varies depending on the species and age of animals.

Table 2 shows the current occurrence of amino acids in animal feed. The differentiation is made with regard to the species, their age and husbandry objectives as well as the frequency of use. According to Table 2, the use of Met, Lys, Thr, Trp and Val in feed for poultry and pigs is already a ‘common practice’ or at least ‘partly used’. But as the formulation of feed is getting more and more advanced, the use of further amino acids such as Ile, Leu and even Arg, Cys and His is taking off.

Currently, the use of amino acids in feed for calves, dairy cows or fattening bulls plays only a minor role in the EU. The use of coated Lys and Met in feed for dairy cows could be the next important future application area of amino acids in animal feed in the EU. Free amino acids, in particular the special formulation of Met, are also used in feed for fish and aquacultures. However, in the EU the importance of this application is quite low.

Besides the level of feed efficiency and the numbers of individual species, there are further important drivers for the use of free amino acids in animal feed. One of them is the expansion of organic livestock husbandry. The point is that free amino acids practically cannot be used in organic livestock farming. The Commission’s Farm-to-Fork and the Biodiversity Strategy include the target of reaching 25% of agricultural land under organic farming by 2030. If this target will be applied to animal husbandry, and if the rules on the use of amino acids in organic livestock husbandry will be maintained, the use of (and demand for) feed grade amino acids in animal feed is expected to decline.

Another important driver on the market of feed-grade amino acids is the growing awareness of negative environmental effects of livestock farming, especially with regard to nitrogen emissions. As amino acids help to raise feed efficiency and to reduce N-leakage, the use of amino acids is supposed to increase if regulations to reduce N-leakage are implemented. The use of Life Cycle Assessments (LCAs) for amino acids as proposed by the FAO (FAO, 2019) could possibly reveal further positive effects of feed-grade amino acids. By taking such effects into account, policies could further foster the use as well as the production of amino acids in the EU.

Discussion

Despite the fact that amino acids have been identified as potentially important bio-based products (ECOSYS, 2011; Lammens et al., 2017; Spekreijse et al., 2019), their contribution to the EU bioeconomy has not yet been quantified. Our analysis discloses the main hurdles in data collection as well as the methodological challenges associated with such assessments and provides a first attempt to close existing gaps.

There is an urgent need for detailed production data to assess the contribution of amino acids to the bioeconomy. ‘Feed-grade amino acids’ form a product or application category which does not have a counterpart in official statistical classification. The first step required to conduct an assessment is to identify relevant products and to find out under which activities their production is reported in the official statistics. In our case, we considered all 20 proteinogenic amino acids, and identified under which codes they are reported in official statistics.

Our analysis reveals that 20 amino acids are assigned to ten codes in trade statistics which are linked to nine codes in production statistics. Lys is the only amino acid used in feed that has its own dedicated code in the trade as well as in production statistics. The production and even trade of other amino acids are reported under a number of different codes, each covering a range of products. This fact makes the use of official statistics for other amino acids practically impossible.

But even data for Lys, which has its dedicated code, reveal significant gaps because of the confidentiality of data, and only a rough estimate for production in the entire EU is available. Therefore, the official statistics only provide parts of a database necessary for a comprehensive analysis. The main problem is not only a lack of information specifically on bio-based production, but general data gaps on amino acids caused by a lack of dedicated codes for amino acids and confidentiality of data.

Our finding can be generalised as follows: Data collection and monitoring of the contribution of a specific product group to the bioeconomy is a very challenging and demanding task, especially if no clear link (mapping) to the classification within production and trade statistics is established.

Amino acid production

We conducted a literature review and interviews to collect further information. Our results reveal that the production of feed-grade amino acids in the EU is dominated by three companies. Met produced from fossil-based feedstock is the most important amino acid produced in the EU. Some other bio-based feed-grade amino acids produced through fermentation (Lys, Trp, Ile, Leu and Arg) are produced in the EU by a single producer and their production volumes are quite low.

The production of bio-based amino acids generates about €50 million value-added and provides jobs for about 400 employees. The bio-based share in the total production of feed-grade amino acids in the EU is about 15% and low compared with a share of 70% at the global level. The main reason is the low level or absence of production of Lys and Thr in the EU, because of its disadvantages as a production location due to higher production costs as well as higher environmental standards.

As a consequence, the contribution from the production of bio-based feed-grade amino acids to the bioeconomy in the EU is quite low and is not expected to increase if current operating conditions remain unchanged.

Contribution of amino acids

The assessment of the contribution of feed-grade amino acids to the bioeconomy through their use in animal feed is even more challenging, as in addition to the data gaps identified previously (results in problems by estimation of use quantities), methodological challenges exist.

Generally, this contribution arises in two ways. First, amino acids help to rise feed efficiency and, thereby, decrease the total demand for feed (and negative effects associated with the production of feed), as well as to reduce nutrient leakages (and associated emissions). Second, free amino acids may contribute to reducing the protein content in the feed. A reduced crude protein (CP) diet is seen as one of the options to reduce the demand for soya bean (meals) in the EU. That would not only decrease the dependency of the EU on imported soya bean (meals), but would also help to reduce the overall negative impact coming from feed production, especially associated with land use change and deforestation.

We argue that an LCA analysis could be an appropriate tool to assess the contribution of amino acids to the bioeconomy through their use in animal feed. Currently, the GFLI partners are developing an LCA database and tool, which aims to serve as a reference for assessing and benchmarking feed industry impact and improvement in LCA calculations for feed. As soon as amino acids are included in the database, a more profound assessment will be possible.

In order to get an impression of the contribution of free amino acids resulting from their use in animal feed, we calculate their theoretical already existing positive impact on land use change. This rough theoretical calculation shows that the use of amino acids in feed already helps to avoid the use of millions of hectares of arable land for the production of animal feed.

If these various positive environmental effects stemming from the use of amino acids in animal feed will be recognised in the future, their use in animal feed would increase not only because of the positive effect on costs of animal husbandry.

However, besides this positive driver for the use of amino acids in feed, there might be negative drivers such as a decline in European livestock farming driven by a decreasing demand for animal products or an expansion of organic agricultural production in the EU, which does not tolerate the use of free amino acids in feed.

The contribution of bio-based amino acids to a more sustainable EU bioeconomy is much more significant if not only the contribution through the related production activities, but also the contribution through their use in animal feed is considered.

Table 1: Order of limiting amino acids. (Source: Toride, 2004)

 FirstSecondThird
Growing pigsLysThrTrp
BroilersMetLysThr

Figure 1: The manufacturing and use of feed additives in livestock enterprises.

Table 2: Occurrence of amino acids in animal feed (pigs and poultry) in the EU.

SpeciesCommon practicePartly usedSelective assignment
Poultry   
Laying hensMet, LysThr, Val, Ile 
BroilersMet, Lys, ThrValIle, Arg, Leu, Cys, His
TurkeyLys, Thr, Met  
Pigs   
Fattening pigsLys, ThrVal, Trp 
PigletsLys, Thr, Met, Val, Trp Ile, Leu, Cys, His
SowsLys, ThrMet, TrpArg

Met = Methionine; Lys = Lysine; Thr = Threonine; Trp = Tryptophan; Val = Valine; Ile = Isoleucine; Arg = Arginine; Leu = Leucin; Cys = Cystine; His = Histidine.Viktoriya Sturm, Martin Banse and Petra Salamon, Thünen Institute

This open source paper was condensed for publication in AFMA Matrix. For the full paper visit www.doi.org/10.1016/j.cesys.2022.100073 or send an email to viktoriya.sturm@thuenen.de.

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