Introduction:
The webinar, hosted by Balchem, features presenter Stephen Ashmead, who has over 40 years of experience with Albion Laboratories, a pioneer in organic trace minerals. The session aims to provide a ‘forensic look’ into the science and practical benefits of chelated minerals in animal nutrition.
Main Topics:
1. The Chemistry of Chelation
Mr. Ashmead began by outlining the essential chemical requirements for a true chelate to be formed:
Ligand: The bonding entity (e.g., an amino acid) must contain at least two atoms that can bond to the metal ion.
Heterocyclic Ring: The bonding of the ligand to the metal forms a stable, protective ring-like structure.
Steric Possibility: The spatial geometry must allow the ligand to physically bond with the metal.
Proper Molar Ratios: This is the most critical and often overlooked requirement. The chemical reaction must be balanced, with the correct number of moles of the ligand for each mole of the metal (e.g., 1:1 or 2:1 ratios). An imbalanced ratio results in an incompletely chelated, less effective product.
To illustrate the importance of this protective structure, an analogy from American football was used. An inorganic mineral is like a ‘fumbled ball,’ free for anyone (antagonists) to grab. A 1:1 chelate is like carrying the ball with one hand—offering good protection but still vulnerable. A 2:1 chelate is like carrying the ball with two hands, providing maximal protection against being stripped away by antagonists in the gut.
2. Evidence of Chelate Efficacy Against Antagonists
The presentation reviewed several studies demonstrating the superior performance of chelated minerals, particularly in the presence of dietary antagonists like phytates and thiomolybdates.
In Vitro Cell Model: A study using a Caco-2 intestinal cell line showed that a zinc amino acid chelate had significantly higher zinc transport through the cell layer compared to inorganic zinc sources, both with and without the presence of the antagonist IP6 (phytate).
Broiler Study: In a study with young broilers, a diet containing a zinc proteinate (a chelate) and an antagonist resulted in growth performance statistically identical to a positive control diet with no antagonist. Other forms, including inorganic zinc, performed significantly worse, showing no improvement over the negative control.
Ruminant Studies: Research in steers and heifers demonstrated that copper chelates (glycinate and proteinate) provided significant protection against thiamolibidate antagonists. This was evidenced by higher plasma copper concentrations and superior relative bioavailability compared to copper sulfate. The chelated forms effectively overcame the negative effects of the antagonist.
Q&A Session:
The session addressed several key audience questions:
Bond Strength: Chelates can be too strong (e.g., EDTA), preventing the mineral from being released for use. Amino acids are in the ‘sweet spot,’ providing protection while still allowing for release and utilization by the animal.
Chelate vs. Complex: All chelates are complexes, but not all complexes are chelates. A true chelate is defined by its protective heterocyclic ring structure, which offers superior protection against antagonists.
Absorption: The prevailing theory is that chelates can be absorbed intact through amino acid pathways, though direct evidence is limited.
Proving Chelation: Laboratory methods like Fourier-transform infrared spectroscopy (FTIR) are used to confirm the existence of the specific metal-ligand bonds that form the chelate ring.
OTM vs. Inorganic Ratio: There is no single ideal ratio; it depends on the specific needs of the animals, and nutritionists often use a combination (e.g., 50/50, 70/30) to balance cost and efficacy.
Conclusion:
Mr. Ashmead concluded that dietary antagonists are unavoidable in feed and water. Properly formed organic trace minerals (chelates) are scientifically proven to provide the most effective protection against these antagonists. This leads to higher bioavailability and better utilization of minerals compared to inorganic sources. Therefore, using well-formed chelates serves as a reliable ‘insurance policy’ to maximize mineral nutrition, animal health, and overall performance.
