Question

What is the digestion. absorption, and utilization of minerals in horses? does it change as they age?

Answer 1

DIGESTION

Digestion in horses refers to breakdown of complex molecules in the ingested food into simple absorbable molecules. This may be either mechanically in mouth/ by gut mobility or may be chemically by action of enzymes in gut. The small intestine is primary site of mineral absorption.

ABSORPTION

Absorption in horses is the process of movement of digested simple molecules into the blood through the gastric wall.

Mineral absorption in horses is roughly determined by amount of mineral remaining manure, compared with the amount contained in the ingested feed. Mineral absorption depends upon pH balance of gut. For some minerals, absorption can significantly be increased by "chelating". Chelation is a process that bonds minerals to two or more amino acids to form stable biochemical ring compounds.There are several interaction between minerals such as between calcium and phosphorous, between zinc and copper, or between zinc and calcium. The  average absorption of calcium varies between 50% to 75%, while phosphorous is less utilized at about 30% to 55%. iron absorption is even less than 15%. Zinc range is from 5% all the way up to 90%, but upward of 100% of ingested sodium is absorbed. These are all get transferred through gut wall and into the blood stream where the minerals ate transported and utilized at various parts.

UTILIZATION OF MINERALS

This include utilizing the absorbed minerals for normal body functioning, for synthesizing cellular constituents.

Following mentioned different minerals and their functions.

Bone development -- Ca P Mg Mn Cu

Muscle development -- P S Zn Se

Skin and claw health -- Zn Cu Mn

Nervous system -- Mg P Cu

Disease resistance -- Cu Zn Mn Se

Age in horses negatively impacts multiple body systems, especially gastrointestinal tract. Decreased saliva production is also observed. Collectively all these reduce digestion, absorption and utilization of minerals in horses. In horses old age often affects health of teeth. This may alter the size of the feed particles in gut which is turn effect digestive physiology from saliva production and passage time to microbial fermentation.