logo nut

Search

Balanced Equine

Facebook

Many nutritionists/scientists/vets consider hair testing for overall nutrient balance pointless. Nutritionists can't use results for balancing or consider hair testing credible in the face of such significant research. 

Hair can be analysed for a variety of substances, including drugs, but in nutritional terms hair analysis refers to hair mineral levels. Minerals reach hair via the blood so it's going have the same limitations as blood testing since hormones control the levels of many of the minerals giving little indication of the status for the rest of the body.

Hair testingThe kidneys will rapidly excrete minerals when they are higher than a tight range, electrolytes like potassium are a good example. The liver can remove minerals before they reach hair.

It can't tell mineral balance even if the totals were credible as it doesn't indicate whether it's due to a deficiency in the first place or competition with another mineral or the body had a high need at that time. Hair can be useful for some heavy metals and selenium but from a nutrition point of view hair testing is pointless. This article by Dr Sarah Ralston VMD (Rutgers University) is about the limitations of blood testing but since hair is supplied by blood, it's relevant: http://esc.rutgers.edu/fact_sheet/diagnosis-of-nutritional-problems-in-horses/

There's been many studies which have demonstrated that many factors other than diet affect the mineral concentrations in hair. Things that affect the mineral levels in hair testing include the time of year, location on the body (different parts of the body test differently, even if they are the same hair colour), breed, age, hair colour, shampoo residues, airborne contamination, sweat, dust on the horse, soil on the horse (even if the horse looks clean), all make a difference. It's not uncommon for hair mineral analyses can't tell the difference between minerals that are on the surface of the hair and those that are actually inside the hair.

One study found higher concentrations of zinc in different colours of hair on the same animal. The same colour hair on different breeds of cattle eating the same food and in the same paddocks produced different mineral levels. Researchers found the age of calves/cows in the same paddock eating the same feed tested for different levels of minerals. Researchers found differences in mineral content of calf hair in calves by different sires - calves were all together and being fed same food.

Animals tested all year round showed different mineral level at different times of year, even though they were eating the same thing. There has been more success with hair testing for arsenic and cadmium, but even such things as age, sex, and length of hair, have been demonstrated to affect the testing for arsenic.

There is a huge body of research on hair analysis, and not one scientific paper has found any evidence that it is in any way effective for balancing the intake (that I know of). One vet researcher sent hair from one horse as separate samples and got very different results. If you know of a study and have a link, I'd love to read it.

Dr Eleanor Kellon discusses the limitations of hair testing in NRCPlus and Dr Ann Nyland researched this in great detail in her book 'Natural Horse Care The Right Way'.

The best and most accurate approach is to have the intake tested (pasture/hay and so forth) and the diet balanced. Soil testing is valuable for long term soil treatment and improving pastures but not useful for determining what is in your horse's intake. Read more about soil testing...

Further reading:

Anke M (1965) Major and trace elements in cattle hair as an indicator of Ca, Mg, P, K, Na, Fe, Zn, Mn, Cu, Mo and Co. 2. Relationship to cutting depth, hair type, hair color, hair age, animal age, lactation state and pregnancy  Arch. Tierzucht. 15: 469

Anke, M (1966) Major and trace elements in cattle hair as an indicator of Ca, Mg, P, K, Na, Fe, Zn, Mn, Cu, Mo and Co. 3. Effect of additional supplements on mineral composition of cattle hair  Arch. Tierzucht. 16: 57

Barrett S (1985) Commercial hair analysis. Science or scam? JAMA. 1985 Aug 23-30;254(8):1041-5. 
http://www.ncbi.nlm.nih.gov/pubmed/0004021042

Combs DK, Goodrich RD, Kahion TS and Meiske JC (1979) Effects of nonnutritional sources of variation on concentrations of various minerals in cattle hair Minnesota Cattle Feeders Rep. 54

Combs DK, Goodrich RD and Meiske JC (1982), Mineral Concentrations in Hair as Indicators of Mineral Status: a Review  JAnim Sci 54:3

Combs DK (1987) Hair analysis as an indicator of mineral status of livestock. J Anim Sci. 1987 Dec;65(6):1753-8.
http://www.ncbi.nlm.nih.gov/pubmed/3327852

Fisher DD, Wilson LL, Leach RM and Scholz RW (1985) Switch hair as an indicator of magnesium and copper status of beef cows Am.]. Vet. Res. 46:2235.

Hambidge KM, Franklin ML and Jacobs MA (1972) Hair chromium concentration: effects of sampling, washing and external environment Amer. J. Clin. Nutr. 25:380

Hambidge KM (1982) Hair analyses: worthless for vitamins, limited for minerals. Am J Clin Nutr. 1982 Nov;36(5):943-9. 
http://www.ncbi.nlm.nih.gov/pubmed/7137078

Hammer DI, J. Finklea JF, Hendricks RH, Hinners TA, Riggan WR and Shy CM (1972) Trace metals in human hair as a simple epidemiologic monitor of environmental exposure  In: D. 0. Hemphill (Ed.) Trace Substances in Environmental Health, V.A. Symposium, Univ. of Missouri, Columbia, 25

Kievay LM (1973) Hair as a biopsy material, ili. Assessment of environmental lead exposure Arch. Environ. Health 26:169

Kempson IM and Skinner WM (2012) A comparison of washing methods for hair mineral analysis: internal versus external effects. Biol Trace Elem Res. 2012 Dec;150(1-3):10-4. doi: 10.1007/s12011-012-9456-z. Epub 2012 May 27.
http://www.ncbi.nlm.nih.gov/pubmed/22639387

Kopito L, Byers R and Schwachman H (1967) Lead in hair of children with chronic lead poisoning New England. Med. 276:949

Miller WJ, Powell GW and Pitts WJ (1965) Factors affecting zinc content of bovine hair  J.Dairy Sci. 48:1091;

O'Mary CC, Butts WT Jr., Reynolds RA and Bell MC (1969) Effects of irradiation, age, season and color on mineral composition of Hereford cattle hair  Anita. Sci. 28:268

O'Mary CC, Bell MC, Snead NN and Butts WT, Jr (1970) Influence of ration copper on minerals in the hair of Hereford and Holstein calves J. Anim. Sci. 31:626

Petering H0, Yeager DW and Witherup SO (1973) Trace metal content of hair Arch  Environ. Health 27:327

Powell GW, Miller WJ, Morton JD and Cliffion CM (1964) Influence of dietary cadmium level and supplemental zinc on cadmium toxicity in the bovine 
I. Nutr. 84:205

Reinhold JG, Kfoury GA and Arslanian M (1968) Relation of zinc and calcium concentrations in hair to zinc nutrition in rats Nutr. 96:519

Seidel S, PhD; Kreutzer R, MD; Smith D, DrPH; McNeel S, DVM and Gilliss D, MD (2001) Assessment of commercial laboratories performing hair mineral analysis JAMA. 285:67-72.

Underwood EJ (1977) Trace Elements in Human and Animal Nutrition (4th Ed.) New York.

Van Koetsveld EE (1958) The manganese and copper contents of hair as an indication of the feeding condition of cattle regarding manganese and copper T/dsehr. Diergeneesk 83:229

Wysocki AA and Klett RH (1971) Hair as an indicator of the calcium and phosphorus status of ponies Journal of Animal Science 32(74-78)
http://www.cabdirect.org/abstracts/19711408318.html;jsessionid=1FD3AA310A805CCC7ABB17F816BC1BF9

Dr Ann Nyland 2009 Natural horse care the right way, Chapter 3 Soil testing and hair analysis

Dr Eleanor Kellon VMD NRCPlus, Chapter 2 Tools
http://www.drkellon.com/

Best Guess

Hoof Rescue

Hoof Rescue +Se

Mov-Ease