Pigs and poultry require various amino acids from their feed because they cannot produce them themselves. These are known as essential amino acids. For pigs and poultry, the amino acids lysine, threonine, and methionine are typically the ones that are insufficient. A new project funded by Organic RDD 10 under the Danish Agricultural Agency aims to develop a method for producing amino acids suitable for organic feed.

Organic amino acids to reduce nitrogen emissions

The production of organic amino acids is intended to enable organic pigs and poultry to be fed with less protein, thereby reducing their nitrogen excretion in the form of unused protein and amino acids. Currently, free amino acids cannot be added to organic feed because they are either produced using genetically modified microorganisms or created through a chemical process.

Optimal composition reduces protein needs

The optimal composition of amino acids is achieved by combining different raw materials in the feed mix. In conventional production, free amino acids can be added to meet the animals' needs, which allows for a reduction in the protein content of the feed without reduced productivity. However, this strategy cannot be employed in organic production. Consequently, animals are fed with excess protein to ensure they receive enough essential amino acids, resulting in surplus amino acids being excreted into the environment through manure and urine.

Production by fermentation

In the project, researchers will produce high levels of lysine, threonine, and methionine using a specific form of fermentation. One of the bacteria the researchers are investigating is Corynebacterium glutamicum, which is also used in the industrial production of amino acids. However, here they use a genetically modified version prohibited in organic farming. Instead, researchers will select suitable substrates for fermentation and isolate natural mutants of bacteria that can grow and produce enough of the amino acids. This will involve extensive screening using biosensors.

“Our partners at DTU have a significant amount of work to do,” says Professor Jan Værum Nørgaard, the project leader.

“They have experience with this technology in other contexts, but here we need to adapt it for the production of amino acids that can be used in organic contexts, which comes with its limitations.” Additionally, choices will be made based on organic and sustainable principles.

“We could opt to use Chinese soy in the process because it's cheap,” says Jan Værum Nørgaard, “but we should also look toward local raw materials with high protein content.”

Nutritional value of the products

If the researchers succeed in developing products with elevated amounts of the three amino acids, these products will be analyzed to determine their nutritional value, both through chemical analysis and in a rat experiment. “This is a high-risk project, and that's why we won't progress beyond the laboratory level,” Jan Værum Nørgaard elaborates. “However, we expect to be able to scale up later and demonstrate the feasibility of producing larger quantities.”

Challenging organic legislation

In organic farming, the use of ammonia, typically produced through a process that requires significant energy and relies on fossil fuels, is prohibited. “However, there are sustainable methods for producing ammonia on the horizon. These should align with organic principles. Therefore, we would like to engage in dialogue with Danish and European policymakers to discuss the possibilities of including such products in the future,” concludes Jan Værum Nørgaard.