New Research Shows Greater Bioavailability of Chelated Zinc in the Presence of Antagonists
Karen Wedekind, PhD, Senior Research Scientist, Comparative Nutrition, Novus International
Zinc plays a cross-functional role in animals, impacting gene expression, DNA and protein synthesis, cell signaling, cell division and animal growth, immune development and function, synthesis of structural proteins such as collagen and keratin, bone and tissue development, reproduction and defense against oxidative stress.
Zinc deficiency can negatively impact one or more of these processes. Therefore, zinc is typically supplemented in all animal diets, either as inorganic trace mineral salts, like sulfates, chlorides and oxides, and/or organic trace minerals. While inorganic trace minerals are relatively cheap, they suffer from poor bioavailability, or the degree to which an ingested nutrient is absorbed in a form that can be utilized in metabolism by the animal, as compared with some organic trace minerals. Poor uptake of inorganic trace minerals is mostly due to antagonisms and interactions in the animal system. An example of zinc antagonism occurs when there is an excess of calcium and/or phosphorus.
In a recent study published in the Open Access Animal Physiology journal, the bioavailability of MINTREX® Zinc was compared with zinc sulfate in Cobb 500 broiler chicks with two dietary conditions:
- Zn-deficient corn-soybean meal diet
- a Zn-deficient corn-soybean meal diet containing elevated calcium and phosphorous as antagonists
The results showed significantly greater Zn bioavailability for MINTREX® Zn relative to zinc sulfate as judged by:
- Total tibia zinc (μg) (161%)
- Tibia zinc concentration (μg/g; 165%)
- Small intestinal metallothionein mRNA expression (248%)
The results also showed zinc sulfate was antagonized to a greater extent than MINTREX Zn. Bioavailability of MINTREX Zn relative to zinc sulfate was 441percent (μg total tibia Zn), 307 percent (μg/g tibia Zn) and 426 percent (metallothionein). Therefore, feeding MINTREX Zn offers advantages over inorganic zinc, especially in diets containing antagonisms such as high levels of calcium and phosphorous, which may occur in certain livestock diets, but is common in pet food.
For the full journal article, click here.