Description

Copper glycinate refers to the coordination complex of copper(II) with two equivalents of glycinate, with the formula [Cu(glycinate)2(H2O)x] where x = 1 (monohydrate) or 0 (anhydrous form). The complex was first reported in 1841, and its chemistry has been revisited many times, particularly concerning the isomerisation reaction between the cis and trans forms first reported in 1890. All forms are blue solids with varying degrees of water solubility. A practical application of the compound is as a source of dietary copper in animal feeds.

Importance

Glycine, as a component of chelate, is the most easily assimilable amino acid, which, with its wide range of applications, additionally improves the values of this additive. Copper is one of the microelements used in combination with amino acids. This element has a broad spectrum of action, which makes it a participant in many metabolic processes in the organism. Thus, it can have a material impact on the health status of animals[1]. Copper deficiency contributes to increased permeability and reduced strength of collagen, which can be a reason for many disorders in the organism.

Uses

Copper (Cu) is essential for animal growth, erythropoiesis, and metabolisms. Copper sulfate (CuSO4) has been used as an additive at high doses to reduce diarrhea frequency and improve piglet growth performance over the last decades. However, Cu chelate with amino acid or peptide (organic Cu) is a potential substitute for CuSO4 in the feed industry. 

Compared to CuSO4, finishing pigs supplemented with Cu glycinate (Cu-Gly) exhibited increased Cu utilization and an abundance of Clostridiaceae_1 in the colonic content. The effects of dietary Cu on the gut microbiota may depend on the experimental conditions, including the pig breed, copper source, and dosage. Lei et al. found that dietary Cu-Gly supplementation increased the feed intake and plasma IGF-1 and decreased fecal microelement contents compared to CuSO4 supplementation[2]. Cu-Gly supplementation elevated the abundance of the Lachnospiraceae family, and the Lachnospiraceae_XPB1014_group genus, and CuSO4 supplementation increased the abundance of the Synergistetes phylum and the Peptostreptococcaceae family.

It could be used in cattle to increase dairy yields. Subcutaneous injections of 400 mg copper glycinate per year were necessary to maintain plasma copper concentration above 8 p mol/L in cows grazing pastures grown on peat soils or copper deficient areas in southeast South Australia. Below this concentration, symptoms of hypocupraemia, mainly yellow tip to hair, diarrhoea, and poor growth, were noted[3-4].

Side effects

Too much copper can cause nausea, vomiting, stomach pain, headache, dizziness, weakness, diarrhea, and a metallic taste in the mouth. Copper toxicity is rare but can cause heart problems, jaundice, coma, and even death. DO NOT use copper supplements if you have diarrhea.

References

[1] Kwiecień, M. et al. “Effect of copper glycinate chelate on biomechanical, morphometric and chemical properties of chicken femur.”Annals of Animal Science (2014).

[2] M. P. B. Deland. “COPPER ADMINISTRATION TO YOUNG CALVES: ORAL DOSING WITH COPPER OXIDE COMPARED WITH SUBCUTANEOUS COPPER GLYCINATE INJECTION.” Australian Veterinary Journal 55 10 (1979): 493–494.

[3] S. Oon,  B. U. Ihle,  C-H. Yap. “Acute copper toxicity following copper glycinate injection.” Internal Medicine Journal 36 11 (2006): 741–743.

[4] Hulong Lei. “Comparison of the Microbiome-Metabolome Response to Copper Sulfate and Copper Glycinate in Growing Pigs.” Animals 13 3 (2023).