Feedstuffs grown in certain geographic areas may be marginal or de icient in speci ic elements. Thus, poultry diets usually require supplementation to ensure an adequate intake of trace minerals. The aim of this paper was the assessment of calcium (Ca), phosphorus (P), magnesium (Mg) and sodium (Na) content in the mixed feeds from two different production systems (organic and conventional). Were analyzed ten samples of mixed feed used for the feeding laying hens from Brown hybrid at the age of

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... 7 weeks in two units in Romania. Sampling and the preparation of samples were performed in compliance with the rules of the standards in force in Romania and harmonized with EU legislation (ISO 6869:2002); the method for the determination used was spectrophotocolorimetry method (UVmini 1240 SHIMADZU) for P, and for Ca, Mg and Na was assessed by atomic absorption spectrometry method. Analysis of mixed feed samples revealed statistically signi icant differences (p≤0.05) between the two systems (organic vs. conventional) for the P content (0.25 vs. 0.26%) and Mg content (0.26 vs. 0.28%). Statistically insigni icant differences (p≥0.05) between the two systems (organic vs. conventional) were found for the Ca content (2.93 vs. 2.97%) and Na content (1.706 vs. 1.712%).