I always considered dirt eating to be an abnormal behavior in horses and
other animals—until I had my eyes opened by a book on how wild animals take care of themselves. Wild Health: Lessons In Natural Health From T e Animal Kingdom is a wonderful book by biologist Cindy Engel, PhD, in which she discusses scientifi c observations of self-medication in wild animals. Aſt er reading that book, I paid more at ention to when the horses in my practice ate dirt, and to where, how and why. Here’s what I’ve learned.
D
irt eating is almost always a normal behavior in horses. T at’s not to say that every horse should eat dirt every day (although they do,
in trace amounts). It’s simply to note that deliberately seeking and eating larger amounts of dirt is a normal behavioral response to some physiological need. In other words, in most cases it seems to be a form of self-supplementation or self-medication. But before I go on, let me make a correction to our
collective view of dirt. “Dirt” is much more than an inert brown substance that messes up our clothes and gets stuck under our fi ngernails. Healthy dirt—or soil, as it should be called—is a living, dynamic ecosystem of organic mat er, a veritable universe of microbes (bacteria, fungi, other tiny organisms), minerals, water and plant roots, to name just the things we’re most interested in here. And the naturally occurring mineral licks that are frequented by wild animals oſt en turn out to be mineral-rich clay deposits or salt pans.
THE SALT MYTH Sa l t
(sod ium
chloride) is a bit of a red herring here, because we humans tend to think that ev- erything needs salt. I confess to being a salt junkie myself. I love the taste of salt! Many animals do, too, although sa l t- seek ing and salt-eating doesn’t necessarily argue for salt defi ciency. Rather, it muddies the waters of our investigation by confusing need with want or desire. We need more salt when we’ve lost more sodium in
one thing because we indulged in another. (Some interesting parallels with other aspects of life...) So, are horses looking for salt when they eat dirt?
Probably not in most instances, particularly as most people with working horses are obsessive about feed- ing extra electrolytes, whether the horse needs them or not. Besides, as sodium does not form a major component of most topsoils, the sodium-deficient horse would have bet er luck licking his owner. What, then, are they looking for? T e various other reasons a horse may eat dirt are summarized in the box on page 28. We’ll go through the three most important ones.
MINERALS Even seemingly well-fed horses may go looking
Many animals love salt, al- though salt-seeking and salt-eating doesn’t necessar- ily argue for salt defi ciency.
for supplemental minerals if their diets contain insuf- fi cient quantities of bioavailable minerals. T e diet doesn’t just need to contain a suffi cient amount of the necessary minerals, the minerals must also be in a form the body can absorb and put to good use. Not to take you unwillingly back to chemistry class, but if the mineral is bound to another element or molecule with a very stable chemical bond, then much of the ingested mineral passes right on through the gut, to be discarded onto the manure pile or into a heap on the pasture. That is the fate of some common mineral supplements, whose bioavailability may be less than 30%. T at means most of what was fed might just as well have been thrown onto the ground. In comparison, the minerals found in
plants and other living things have already been absorbed and assimilated into the organ- ism’s biochemical processes. Here, the desire for
urine, sweat and other secretions or excretions than we’ve got en from our diets, or when we’ve drunk an excess of water (or tea, in my case). However, under ordinary circumstances, we get suffi cient sodium in our food. We want more salt because we like the taste of it.
However, when we take in more sodium than we need, we then have to drink more water, oſt en not stopping until we’ve taken in too much, which makes us crave salt. So, around and around we go, always in need of
stability (of chemical bonds) is counterbalanced by the need for lability or freedom, because biochemical processes are all about exchange—the dynamo eff ect of constant trading of protons and electrons, which powers the process of life. T e minerals in living sys- tems are actively involved in these exchanges, so their chemical bonds tend not to be as stable as those of some inorganic forms. T us, organic forms of minerals tend to be more bioavailable in the diet than inorganic forms of the same mineral (although that varies somewhat with the mineral and its origins).
continued next page
WWW.TRAILBLAZERMAGAZINE.US • December 2011 | 27
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100