The Reference Intervals of Hair Trace Element Content in Hereford Cows and Heifers (Bos taurus)

The objective of the present study was to assess hair trace element content in Hereford heifers and cows (Bos taurus) living in South Ural region and calculate the site-specific reference intervals. Hair trace element content in 150 cows and heifers farmed in the Southern Urals of Russia was assessed using inductively coupled plasma mass-spectrometry. Dietary trace element content corresponded to the adequate values as estimated by recommendations of USSR State Agriculture Committee and U.S. National Research Council. Comparative analysis demonstrated that heifers are characterized by significantly higher hair Se (3-fold), Hg (4-fold), and Sn (46%) content, whereas cows had significantly higher levels of hair Co (56%), I (33%), Si (2-fold), V (27%), B (55%), Cd (19%), Pb (47%), and Sr (23%). At the same time, no significant group difference in hair Cr, Cu, Fe, Li, Mn, Zn, As, and Ni was detected between Hereford cows and heifers. The reference intervals and 90% confidence intervals for the lower and upper limits were calculated in agreement with the American Society for Veterinary Clinical Pathology Quality Assurance and Laboratory Standard Guidelines.