en Relations between macro and trace elements in the serum of dairy cows in Urmia, Iran تخصصي Special پژوهشي orginal article Serum concentrations of the major nutritive elements, Mn, Mo, Cu, Fe, Mg, Ca, Na, K, P and Cl, and their interrelationships were evaluated in 20 dairy herds in Urmia, northwest of Iran. Values were determined by atomic absorption, auto analyzer spectrophotometry and flame photometer. Mean Mn, Mo, Ca, P and K were less and Fe and Cu were higher than the reference values. Herd effects were present for the majority of elements, but not K, Na, Fe and Cl. The strongest correlations were positive between Cu/Mo and Ca/Mn, with weaker but significant positive correlations between Mn/Ca, Mo/Cu, Fe/K and Fe/Cl. Negative correlations existed between Ca/K, Ca/Mo, Mg/Mo, Mg/Mn, Mg/P, Fe/Mn, and Fe/Mo. Correlations coefficients with Mo and to a lesser extent Mn were higher than for other elements. There were two principle components in the dataset, explaining 12 and 11% of the variation respectively, involving mainly Fe and Mo in the first component and Ca and Mo in the second. It is concluded that Fe, Mo, Mn and Ca concentrations in the serum of dairy cows in this region were of particular importance in explaining variation in the element concentrations in serum of cows in Urmia, Iran. blood serum, dairy cows, Iran, macro-elements, trace elements 23 30 http://ijrabms.umsu.ac.ir/browse.php?a_code=A-10-97-3&slc_lang=en&sid=1 N Norouzi Ali_ramin75@yahoo.com 1003194753284600401 1003194753284600401 No Veterinary College, Urmia University, Urmia, Iran A.G Ramin Ali_ramin75@yahoo.com 1003194753284600402 1003194753284600402 Yes Veterinary College, Urmia University, Urmia, Iran S Asri-Rezaei Ali_ramin75@yahoo.com 1003194753284600403 1003194753284600403 No Veterinary College, Urmia University, Urmia, Iran L Kalantary Ali_ramin75@yahoo.com 1003194753284600404 1003194753284600404 No Veterinary College, Urmia University, Urmia, Iran C.J.C Phillips Ali_ramin75@yahoo.com 1003194753284600405 1003194753284600405 No Centre of Animal Welfare and Ethics, School of Veterinary Science, The University of Queensland, Australia