The effect of mineral supplementation on the concentration of microelements in blood of milking cows.

The purpose of this study was to determine the effect of inorganic and mixed supplementation on mineral status in milking cows. Sixty milking cows were randomly divided into 3 groups of twenty animals in each. All cows were fed a common diet used for milking cows. In addition, cows in group I were fed with inorganic supplementation, in group 2 with a mixture of inorganic and organic supplementation, and animals in group 3 had no supplementation (controls). Blood samples were taken and delivered to the laboratory <1 hour, centrifuged for 5 minutes at 3000 times/min and kept at - 20 degrees C. Levels of microelements in sera were determined by atomic absorption spectrophotometry "Zeeman 3030". Iodine concentrations in blood plasma were determined by Inductively-Coupled Plasma Mass Spectrometer ELEMENT-2. Our results revealed that the level of Mg, Zn, Cu, Co and I in the blood of experimental cows in groups 1 and 2 significantly increased after 3 and 2 month of diet supplemention as compared to controls (group 3). Furthermore, the level of Mg, Zn, Cu, Co and I in the blood cows of group 2 on mixed supplemention after 3 month was respectively on 5.81%, 1.26%, 1.03%, 3.44% and 2.86% higher compared to cows on inorganic supplementation (group 1). The results from this study demonstrated that mineral supplemention can have a marked effect on the mineral elements level in milking cows and are essential for keeping microelements level within physiological norm.