Lysine Analysis of Animal Feed

Lysine is a building block of proteins and is one of the most crucial amino acids in animal nutrition. In this article, we explore the importance of lysine in diets for animal health and performance and look at why quantifying lysine with amino acid analysis can help feed manufacturers develop feed ingredients that are not only optimal for livestock but also kinder to the environment.

Lysine in Animal diets

Lysine is one of the few building blocks of proteins that cannot be synthesised by the animal body. It is an essential amino acid involved in many biological processes. For instance, it is required for the synthesis of proteins and muscle development, synthesis of cytokines, gene expression and lymphocyte proliferation.¹ Animals, like humans, acquire lysine from the food they eat. One of the main sources of lysine is meat, and although it is present in plant-based sources that are rich in protein, such as soybean meal, their levels are usually lower. As its availability also affects the intake of other amino acids, lysine is considered to be the first limiting amino acid in many plant-based feed ingredients. In particular, monogastric species must receive sufficient amounts not to compromise their growth, immune system and overall health. Lysine analysis of feed is, therefore, crucial to ensure the animal’s nutritional requirements are met.

What is Lysine Analysis?

Lysine analysis refers to the process of quantifying the amino acid lysine in a sample. This can be achieved by analytical techniques such as the post-column detection method offered by Alta Bioscience. Our amino acid analysis method can be broken down into three main steps: hydrolysis, separation and detection.

First, the sample is hydrolysed by acid. Hydrolysis is a chemical step that breaks up the bonds between amino acids that make up proteins. As the chemical structures of amino acids differ, it is then possible to separate and purify them by ion exchange chromatography. Finally, after coupling with ninhydrin, the amino acids, including lysine, can be detected by photometry. The produced colour intensity is proportional to the concentration of amino acid. Consequently, this allows measurement of the precise amount of lysine and other amino acids present in the sample.

Why Analyse Lysine in Animal Feed?

Feed Nutrient Optimisation

Formulators often supplement feed with synthetic lysine or by using richer alternative sources of proteins. This is to ensure that animal diets are formulated to meet or exceed the levels of limiting amino acids. Using excess lysine is generally considered to be safe. However, a recent study in pigs showed that this may lead to reduced appetite in the animals, hence causing a reduction in the food intake and consequently in growth.² Therefore, this highlights the importance of testing lysine in feed to ensure its amount is optimal.

Cost Optimisation

Analysis of feed products provides crucial nutritional data about the ingredients being used in feed formulations. In particular, it allows feed formulators to reduce the utilisation of expensive feed ingredients by compensating for any lysine deficiency with supplementation or by using inexpensive alternative protein sources.³

Developing Feedstuffs that are Kinder to the Environment

Feed analysis often measures the crude protein content of feedstuff. However, this analysis does not represent the true protein content, as non-protein nitrogen is also included. On the contrary, lysine analysis provides more accurate data that can help feed manufacturers decrease the dietary concentration of crude protein used while ensuring that the feed formulations stay nutritionally balanced. Doing so may help decrease the amount of animal waste produced, decrease ammonia emissions into the air, and decrease nitrogen excretion to the environment.

Conclusion

Amino acid analysis of feed provides accurate nutritional protein data, which are essential for formulating balanced and tailored diets that address the unique nutritional needs of different livestock species. In particular, the analysis of lysine, a limiting amino acid in many animal diets, ensures that the animals receive the amounts they require while developing cost-effective and more environmentally friendly solutions.

At Alta Bioscience, we support feed manufacturers and formulators by providing precise and detailed nutritional information about their feed ingredients and finished produce. Our amino acid analysis service is accredited to ISO 17025:2017, and we can accurately quantify protein and amino acid levels in a range of samples, such as:

• Feedstuffs and fodder
• Plant-based ingredients
• Dried distillers’ grains with solubles (DDGS)
• Protein hydrolysates
• Raw materials
• Food waste
• Animal by-products
• Fish meal
• Insect proteins

Contact our team today to see how we can help with your amino acid analysis requirements. You can also download our technical document below.