Reference intervals of chemical elements in the horse's mane of the English thoroughbred
The purpose of this study was to assess the content of essential and toxic trace elements in the hair from the mane of stallions and mares of the English thoroughbred bred in the biogeochemical province of the North Caucasus. For this purpose, hair samples were taken from clinically healthy stallions (n=190) and mares (n=94), 3-7 years old. Hair color is black. The elemental composition of hair was determined according to 20 indicators using atomic emission and mass spectrometry (AES-ICP and MS-ICP). Statistical processing was performed using Mann-Whitney U-test. For data processing, the software package «Statistica 10.0» («Stat Soft Inc.», USA) was used. Significant gender differences were identified in 10 essential elements: Co, Cr, Fe, I, Mn, Zn, Li, Ni, Si,V, and 6 toxic elements: Al, As, Pb, Sn, Sr, Hg, in that respect reference intervals we calculated separately according to gender. Reference intervals of the main essential and toxic elements in the hair from the horse's mane of the English thoroughbred ere calculated in accordance with the recommendations of the ASVCP Quality Assurance and Laboratory Standard Guidelines. Reference intervals (µg/g) were established for stallions according to Co (0.006-0.112), Cr (0.026-0.40), Cu (4.29-6.78), Fe (9.99-268.2) , I (0.02-3.87), Mn (0.48-9.35), Se (0.127-0.732), Zn (100.7-170.8), Li (0.01-0.31) ), Ni (0.054-0.464), Si (0.532-29.18), V (0.007-0.328), Al (2.23-136.0), As (0.006-0.099), Cd (0.002-0.03 ), B (0.464-18.9), Pb (0.016-0.5), Sn (0.0016-0.2), Sr (0.926-7.02), Hg (0.0018-0.016); mares according to Co (0.006-0.173), Cr (0.026-0.67), Cu (4.06-7.88), Fe (9.46-591.7), I (0.079-3.47), Mn (0.613-14.6), Se (0.077-0.71), Zn (93.95-166.7), Li (0.012-1.02), Ni (0.075-0.653), Si (1.59- 30.1), V (0.0052-0.823), Al (1.72-192.7), As (0.0066-0.181), Cd (0.002-0.054), B (0.512-5.96), Pb (0.023-0.436), Sn (0.0017-0.133), Sr (1.33-13.49), Hg (0.0018-0.02).