Selected trace element concentrations in goat milk

Goat milk is used for human consumption in both developed and developing country and is suggested as a dietary supplement for consumers with inflammatory conditions and for elderly people. As milk from other species goat milk contains, besides known essential trace elements, also potentially toxic trace elements and other less known minor trace elements whose role, if any, is not known. The aim of this study was to measure the concentrations of Zn, Fe, Cu, Mn, Co, Se, Mo, Li, Ti, V, Co, As, Rb, Sr, Cd, Cs, and Pb in goat milk. Individual milk samples were obtained by machine milking (8:30 am) from 18 Saanen goats at approximately 30 days from parturition. The milk concentrations of the aforementioned elements were analyzed by Inductively Coupled PlasmaMass Spectrometry. The average (± SD) milk concentrations (μg /L) of the investigated elements were as follow: Essential Zn 2138 ± 356; Fe 326 ± 65.6; Cu 48.7 ± 14.2; Mn 19.9 ± 6.1; Co 1.4 ± 0.2; Se 9.3 ± 1.4; Mo 111 ± 36.7; Li 23.7 ± 6.3; Ti 299 ± 24.0; V 0.67 ± 0.09; As 0.57 ± 0.09; Rb 1144 ± 102; Sr 1001 ± 136; Cs 0.9 ± 0.18; Pb 3.6 ± 0.6. The milk concentration of Cd was below the limit of detection, calculated at 0.3 μg/L of milk. Significant (P<0.05) correlation coefficients were observed between some investigated elements: the correlations were positive between Fe and Co (r = 0.81), Ti (r = 0.65), V (r = 0.58), and Sr (r = 0.55), between Cu and Mn (r = 0.53), between Co and Ti (r = 0.71), V (r = 0.66), and Sr (r = 0.49), and between Cs and Sr (r = 0.66), whereas Li was negatively correlated with Mn (r = 0.53) and Ti (r = 0.52). The current study added new data and provided novel information on the concentration of essential, potentially toxic, and minor trace elements in donkey milk.