There is no doubt balanced nutrition is essential for the growth and development of healthy ruminants. Although marginal amounts of trace minerals are needed, they play a fundamental role in animal performance. Trace minerals support metabolism and proper immune function, yet an oversupply of these elements can be toxic and have a detrimental effect on rumen microbes and overall animal performance. Therefore, the precision feeding of trace minerals play an important part in ruminant nutrition.
The Mechanics of Organic, Inorganic and Hydroxy Trace Minerals in Ruminant Animals
A common misconception is that inorganic, organic or hydroxy sources of trace minerals, like Zinc, Copper and Manganese, all undergo similar absorption processes in the ruminant’s small intestine. Mineral absorption includes the various absorptive pathways, with the relevant receptors and transporters for each mineral. The trace mineral source, whether organic or inorganic, is purely the vehicle that delivers the metal to the duodenum where minerals must dissociate to release ionic metals for absorption. Therefore, making the type of bonds in the mineral source more important that any other factor. Metal transporters, specific to each mineral, then actively transport these ionic metals across the intestinal wall and into the bloodstream, thereby regulating mineral homeostasis.
IntelliBond’s unique formulation supports the normal absorptive process, with trace minerals only becoming available for absorption when they reach the small intestine, making it the ideal source of Zinc, Copper, and Manganese. Learn about IntelliBond’s characteristics and abilities in the article below.
Universal Trace Mineral Behaviour in Animal Rumen
Similar mechanisms and receptors absorb trace minerals in the small intestine, whether from inorganic, organic or hydroxy sources. These transporters facilitate the movement and absorption of Copper, Manganese and Zinc from the intestinal lumen into the bloodstream. However, rumen antagonists can negatively affect trace mineral stability as they pass through the rumen. Some of the potential antagonists that can bind to free metal ions in the rumen include iron, molybdenum, phytates, fibre by-products, and sulphur. Binding to these antagonists will reduce the amount of trace mineral unavailable for absorption.
Rapid Breakdown of Inorganic Trace Minerals in Ruminants Proves Problematic
Even though the different sources of trace minerals use similar mechanics, their absorption rates can vary greatly depending on the type of chemical bond. Inorganic trace minerals, for instance, have weak ionic bonds leading to dissociation within the rumen. This rapid breakdown within the rumen creates the opportunity for free metal ions to bind with rumen antagonists, which decreases the availability of trace minerals in the lower gastrointestinal tract for absorption.
Some trace minerals may have to compete for common transporters which further limits the absorption of different mineral. Research has shown that trace minerals are not absorbed while they are still bound to their ligand but must be in the free form to facilitate absorption.
Zinc, Copper and Manganese Absorption
Providing a stable source of Zinc, Copper and Manganese, that slowly becomes available in the intestine will improve absorption and animal performance. Trace minerals have varying levels of bioavailability.
Zinc Absorption for Ruminant Animals
Zinc availability for absorption is about 5-10%. The reason for this low availability lies in its tendency to bind with antagonists in the rumen as well as in the feed. Zinc’s absorption is homeostatically controlled, meaning the dietary zinc concentration within the intestinal lumen determines the expression of Zn transporters from the small intestinal enterocytes.
The two most familiar groups of transport proteins for Zn are the ZIP transporters, involved in the movement of Zn from the intestinal lumen into the enterocytes, and the ZnT proteins facilitating the movement of Zn from the cells, or the influx of Zn into intracellular vesicles.
Copper Absorption in Ruminants
Complex reactions with rumen antagonists cause a typically low absorption rate (1-10%) of Copper in ruminants. These interactions lead to formation of insoluble compounds which is of no benefit to the animal. Copper absorption, like Zinc, is controlled homeostatically and the concentration of the element (Cu) controls the expression of transporters from the enterocyte. Copper absorption does not require energy.
The primary protein involved in Copper’s cellular import is the high-affinity Copper Transporter 1 (CTRl), which is specific to Cu+1. Cu+2 is reduced to Cu+1 before absorption, by a reductase enzyme. Additionally, it is suggested that a major transporter of Fe+2, known as Divalent Metal Transporter 1 (DMT1), is possibly also involved in the transports of Cu2+. Since it plays a role in the transport of various divalent metals in brush border membrane vesicles.
Manganese Absorption in Animal Rumen
With the low absorption rate of 1% (or less) from animal feed, Manganese is somewhat of an enigma. Intestinal absorption of Manganese in ruminants is believed to include the transporter, DMT1. Iron and Manganese compete for DMT1, which may explain the antagonism between these elements.