Assessment of Gender Effects and Reference Values of Mane Hair Trace Element Content in English Thoroughbred Horses (North Caucasus, Russia) Using ICP-DRC-MS.

The objective of the present study was assessment of gender differences in hair trace element content in English Thoroughbred horses (North Caucasus, Russia) using ICP-DRC-MS and calculation of the reference values. Trace element content in mane hair of 190 stallions and 94 mares (3-7 years old) bred in North Caucasus (Russia) was assessed using inductively coupled plasma mass spectrometry. Mane hair Co, Cr, Mn, Li, Si, and Sr levels in mares exceeded those in stallions by 77%, 63%, 64%, 42%, 39%, and 64%, respectively. Hair Fe and Si content was nearly twofold higher in female horses as compared to the males. Only hair Zn content was 5% higher in stallions as compared to mares. In addition, mares were characterized by 63%, 65%, 29%, and 40% higher levels of As, Pb, Sn, and Ni levels in hair as compared to the respective values in stallions. In turn, hair Al and Hg were more than twofold higher in mares than in stallions. The reference intervals of mane hair content (µg/g) for Co (0.006-0.143), Cr (0.028-0.551), Cu (4.17-6.84), Fe (10.11-442.2), I (0.026-3.69), Mn (0.551-12.55), Se (0.108-0.714), Zn (97.43-167), Li (0.011-0.709), Ni (0.060-0.589), Si (0.665-29.12), V (0.006-0.584), Al (1.98-168.5), As (0.006-0.127), Cd (0.002-0.033), B (0.494-16.13), Pb (0.018-0.436), Sn (0.002-0.144), Sr (1.0-9.46), and Hg (0.0018-0.017) in the total cohort of horses were estimated using the American Society for Veterinary Clinical Pathology Quality Assurance and Laboratory Standard Guidelines. The reference intervals were also estimated for stallions and mares bred in North Caucasus (Russia) and may be used for interpretation of the results of hair trace element analysis in horses.

The content of essential and toxic elements in the hair of the mane of the trotter horses depending on their speed.

A study on the Russian trotting breeds was conducted to assess the impact of horses' sporting results and the degree of accumulation of chemical elements in the hair. In the first phase of the research, the elemental composition of the mane hair of trotter horses (n = 215) was studied. Based on these studies, percentile intervals for the distribution of concentrations of chemical elements in the hair have been established, and the values of 25 and 75 percentile adopted as a "physiological standard" have been defined. In the second stage of the research into clinically healthy Russian trotting breeds (n = 56), it was estimated that the sporting results were dependent on the elemental status defined by the hair. The elemental composition of the hair was defined by 25 chemical elements using atomic emission and mass spectrometry. It is established that the mane hair is closely related to the sporting results of trotter horses. Thus, in animal wool with the highest sporting achievements, there were reliably less I, Cr, Co, Li, V, Al, Pb, and Cd, and reliably more Si than the low ones. Differences in individual elements exceeded 200%. As sporting performance diminished, the number of elements within the standard increased. For example, for mares with average speed, there were deviations from the physiological standard by 6 elements (P, Fe, Mn, I, Co, Si), with the low one by 13 elements (P, Fe, Cu, Mn, I, Co, Si, K, Cr, Ni, V, Al, Pb). A comparative estimate of the mineralization of the horses' mane measured by the sum of the amount of substances showed that there was a negative correlation between the accumulation of toxic elements and the speed (r = - 0.59). On the basis of the above, a conclusion is reached on the future use of the mane hair to assess the speed qualities of trotter horses.