Amino Acid Analysis of Feed Products for Optimal Animal Nutrition

Developing cost-effective, nutritionally complete and consistent solutions to optimise the health and growth of livestock and aquatic species are some of the many challenges encountered by feed manufacturers today. Feed formulation lies at the heart of this process, and an essential component is amino acid analysis. This analytical technique plays a crucial role in tailoring animal feeds to meet specific dietary requirements. In particular, it ensures that each essential amino acid is present in the right proportions. In this blog post written by Sarah Hawker, head of Amino Acid Analysis, we explore in detail the significance of testing amino acids when developing animal food products.

Understanding Amino Acids and Proteins in Animal Nutrition

Transforming Feed Quality: Amino Acid Precision vs Protein Content

Historically feed products were formulated to meet basic protein requirements as opposed to ensuring adequate levels of individual amino acids. This approach led to the creation of products with lower quality. Firstly, the methods employed to assess the total protein content of samples frequently produced inaccurately high readings, leading to an overestimation of the protein content. For more details, please see Amino acid analysis methods review: Post-column detection method compared to Kjeldahl and Dumas methods. Secondly, because commonly utilised feed ingredients often contain insufficient levels of specific amino acids required for optimal livestock nutrition.

Amino Acids in Animal Feed

Amino acids are the building blocks of proteins. In the context of animal nutrition, they are categorised as either essential or non-essential. Animals cannot synthesise essential amino acids, and consequently it must be provided through the diet. They can synthesise non-essential amino acids internally, but their availability in the diet remains important for overall protein synthesis.

In many species, diets that are low in single amino acids often limit the growth and health of the animals. Farmers can supplement feed with synthetic amino acids to correct low amino acid levels. Knowing the exact amino acid profile of ingredients is therefore crucial for the formulation of nutritionally complete feeds.

Lysine, for example, is an essential amino acid in swine nutrition. It is available in limited amounts in cereal grains and other vegetable protein sources, so supplementation with synthetic lysine can have significant economic benefits to pig farmers. For instance, it has been shown that it allows an increase in feed consumption, weight gain, and nitrogen retention. ¹

Addressing Specific Nutritional Challenges

Amino acid requirements vary among different animal species due to differences in their physiological and metabolic processes, as well as their dietary habits and evolutionary adaptations. Amino acid requirements also vary depending on the life stage of an animal, its health and stress conditions. For instance, young animals in the growth phase may have higher requirements for certain essential amino acids to support tissue development and protein synthesis. Likewise, pregnant and lactating animals may require feed formulations that support the growth and development of the foetus and the production of milk.

The Role of Amino Acid Analysis in Feed Development

Feed Analysis for Precise Nutrient Formulation

Ingredients might be deficient in certain essential amino acids and may present a high degree of variability in their amino acid levels due to their origin, the presence of anti-nutritional factors that may impact protein quality, inherent batch-to-batch variations and processing conditions. By knowing the exact levels of amino acids in feed ingredients, formulators can optimise diets to minimise excesses or deficiencies, enabling the feed compositions to be adjusted to meet the animals’ nutritional needs and to ensure optimal animal performance.

Economic Feed Formulation

Knowing the internal protein composition of the raw materials also contributes to cost-effective feed formulation, as unnecessary amino acid supplementation can be avoided. For instance, in fish farming, optimising nutrition is critical because feed accounts for approximately 70% of the production costs², and of this cost, the most expensive component is protein. In a meta-analysis of the amino acid analysis requirements of fish and crustaceans conducted in 2023, all studied fish and crustaceans required 10 essential amino acids to be supplied in their diets: arginine, histidine, isoleucine, leucine, valine, lysine, methionine, phenylalanine, threonine and tryptophan³. Of these essential amino acids, lysine and methionine are often the first limiting amino acids, so quantification of these is extremely important to fish feed manufacturers as fish can be fed less protein if requirements for these limiting amino acids are met first.