What is arginine?
Arginine is one of the 20 amino acids in proteins. Its side chain carries a guanidino group, which makes it strongly basic and gives it its role as a nitrogen carrier in metabolism.
Mammals can make arginine through the urea cycle and intestinal metabolism, although in young, fast-growing animals this synthesis may not cover the full requirement. Birds lack a functional urea cycle and excrete nitrogen as uric acid, so they cannot synthesise arginine in meaningful amounts and depend entirely on the diet.
What does it do in animal feed?
- Protein synthesis: needed for growth of muscle and other tissues.
- Creatine synthesis: arginine provides the amidino group for guanidinoacetic acid, the precursor of creatine, which is important for energy metabolism in muscle.
- Nitric oxide: arginine is the precursor of nitric oxide, which is involved in blood flow regulation and immune responses.
- Other metabolites: it is a precursor of ornithine, polyamines and proline, which are involved in cell growth and tissue repair.
- Broilers: an adequate arginine supply supports growth, feed efficiency and breast meat yield; it is studied in relation to heat stress and gut health.
Arginine in low-protein diets
Soybean meal is relatively rich in arginine, while corn and many other cereals are lower. When crude protein in broiler diets is reduced and lysine, methionine, threonine and valine are supplied in crystalline form, the remaining soybean meal may no longer cover the arginine requirement. Arginine is then among the next amino acids to check, together with valine, isoleucine and glycine.
Guanidinoacetic acid (GAA), a creatine precursor available as a feed additive, is sometimes discussed as a way to spare arginine that would otherwise be used for creatine synthesis; how far this applies depends on the diet and should be assessed by the nutritionist.
Interaction with lysine
In poultry, a large excess of dietary lysine can increase the breakdown of arginine and so raise the effective arginine requirement. This lysine-arginine antagonism is one reason why nutritionists look at the arginine to lysine ratio rather than at arginine alone, especially when synthetic lysine is used at high levels.
How is the requirement assessed?
Arginine is formulated on a digestible basis, usually as a ratio to digestible lysine within the ideal protein concept. The appropriate ratio depends on species, age, the protein level of the diet and environmental conditions. Feed-grade L-arginine is added to cover the shortfall left by the raw materials once the earlier limiting amino acids have been balanced.
Quality criteria
- Guaranteed L-arginine content and purity, as stated in the specification.
- Moisture, ash, heavy metals and microbiological quality.
- Particle size and flowability for even distribution in premixes and feed.
- Certificate of analysis (CoA) and lot traceability.
CTF Premix and arginine
Arginine can be included in CTF Premix's vitamin, mineral and custom premixes according to the customer's formulation, alongside other amino acids, vitamins and trace minerals. Our premixes are produced at our Ankara facility under ISO 9001:2015 and GMP, and every lot is supplied with a certificate of analysis and full lot traceability.
This page is for general information. Inclusion rates and product choice should be decided with a nutritionist, taking into account the species, the feed formulation and the applicable regulations.