Page 73 - May 2018 Speedhorse

“There is starting to be some evidence of correlation between intake and deposition in the hair shaft, but we are still working on how to interpret them.”
predict atrial fibrillation (AF) in horses from
a hair sample by looking at levels of calcium, zinc and the zinc/copper ratio, which have been found to be higher in horses with AF.
“One study showed a correlation in horses with Equine Metabolic Syndrome (EMS) and hair analysis. The hair in these horses showed results similar to the hair of people with diabetes. Horses with EMS had differences in the hair makeup in lead, calcium, zinc, sulfur and chromium. EMS horses were found to have elevated levels of lead over normal horses, as well as decreased levels of the other mentioned minerals,” she says. There may be potential for use of hair analysis in diagnostics in the future. Someday we may be able to look at lead or zinc levels in hair and tell whether this is an indica- tion of EMS.
Some people check cortisol levels in hair to see if the horse is stressed. “However, in studies looking at hair cortisol, researchers only found a direct correlation with intensity of exercise. It was more an indicator of intense exercise than it was of stress,” she says. Hair cortisol levels are not an accurate measure of stress.
Hair analysis and blood samples can both be used to check mineral status, but they each have their advantages and drawbacks. “A blood sample gives a picture of what the body is doing right at this point in time, while a hair sample gives a longer-term picture. That’s why using both together can give a better idea of what is really going on,” explains Crandell.
Some people might use a blood sample to see if a horse is deficient in a certain mineral like calcium, for instance, but this might not be an accurate evaluation. “A blood sample may be deceiving because the body is trying
to maintain homeostasis, which keeps the minerals in proper balance, even if it has to
rob one source to help maintain another. It
will be trying to hold calcium level steady, for instance, and balance any excesses or deficien- cies. In that respect, maybe hair is better to measure the calcium, as the body will deposit calcium in the hair according to the level in the diet, rather than trying to maintain the level homeostatically. If you look at the hair roots, the acute intake level would show there, in contrast to levels farther up the hair shaft that would indicate the body’s intake in the recent past. There is starting to be some evidence of correlation between intake and deposition in the hair shaft, but we are still working on how to interpret them,” says Crandell.
“Some of the most fascinating work with hair analysis has been done using plant isotopes to determine what a horse has been eating. Recent improvements in analytical capabilities allow
the study of detailed isotope variations within individual animal tissue samples like hair on
live and dead animals. So far, researchers have found that when a horse eats a plant contain- ing a specific natural isotope, that same isotope can also be identified in the hair. Changes in consumption of plants with different isotopes are reflected rapidly in the hair. Analyzing hair for these isotopes can tell you what the horse was eating at what time period. This technique may be useful to determine what the horse is eating currently, or to learn more about what the horse may have eaten in the past,” she says.
Japanese sTudy
The influence of hair color on trace elemen- tal status in horse hair had already been studied, but a new Japanese study utilized a more recent analytical technique. The particle-induced
X-ray emission (PIXE) is a reliable, rapid, easy and relatively inexpensive diagnostic method.
In this study, 28 elements in mane hair were readily detected by the PIXE method, but gray hair contained significantly greater amounts of copper, titanium and zinc, and lower amounts of other elements including calcium and selenium than in other colored horse hairs.
Those results in horse hair were similar to earlier results found in human and dog hair. When interpreting a result, it should always
be kept in mind that hair color, especially gray hair, influences the concentrations of some ele- ments in horse hair.
The levels of trace elements in biological samples from horses, such as blood and some- times hair, can be used to assess diseases and metabolic disorders. The hair shaft is continu- ously exposed to several elements through con- tact with secretions from oil glands and sweat glands in the skin. Because the concentrations of trace elements are higher in hair than in other body organs and fluids, and the sampling and storage of hair are easier than in other biological materials, some people prefer to use hair as an indicator of trace elemental status
in individual animals. For several elements, significant correlations exist between element concentrations in hair and mineral intake, but these correlations are usually quite low. Non- dietary factors, such as sex, age, contamination and hair color, can affect element levels in hair.
In the Japanese study, samples were obtained from 11 gray, 18 chestnut, and 27
bay horses aged 4–23 years. The horses were deemed healthy and the specimens collected were at least 10 or more mane hairs from the nape area nearest the skin. The colors of hair in gray, chestnut and bay horses were light gray, brown and black. In this study, 28 elements in mane hair were detected by the PIXE method. In the colored hair (chestnut and bay horses), no characteristic difference of trace element concentrations was found in mane hair.
The study findings showed how coat color is associated with concentrations of some major and trace elements. The maximum amounts of copper, titanium and zinc were found in gray hair, followed by chestnut and bay hair. In con- trast, gray hair gave the lowest concentrations of several other elements including selenium and calcium. Thus, the elemental composi- tion of hair seemed to be correlated with color. The influence of hair color had been already demonstrated in humans, cattle and dogs. The maximum amounts of the elements were found generally in black hair of humans.
An earlier study also demonstrated that col- ored hair taken from ponies had higher concen- trations of calcium than white hair taken from the same ponies. Another study demonstrated that the selenium concentration in white hair from Holstein dairy cows was significantly lower than that in black hair. The same result as the one in a cow was obtained in a horse. The conclusion of this research was that we should pay attention to hair color of a horse when measuring the met- als in a selenium-deficient disease.
samples
The typical hair analysis requires a sample of mane, cut close to the skin, at
the roots. Only first 3 inches is needed, with the long ends lopped off. After the lab receives the sample it is then analyzed for a series of mineral levels in the hair and ratios of specific minerals are calculated.
“An analysis of the amino acids in hair for determining protein intake is useless because the actual amino acids put into the hair by the body is not determined by the quantity that is in the body. It has more
to do with the structure of the hair as to which proteins and amino acids are pres- ent,” says Kathleen Crandell.
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equine health