Determination of macro and micro elements in animal feed

In present study, several analysis were performed to determine minerals such as Fe, Cu, Mn, Zn, Mg, Na, K, Ca and P that necessary for animal health and development and heavy metals such as Cd and Pb that excess concentrations may pose harmful effects to human health and the environment in animal feed obtained from Manisa district. The feed samples were milled and homogenized. Dry combustion and microwave digestion procedure were applied to the samples prior to determination of Fe, Cu, Mn, Zn, Mg, Na, K, Ca, P, Cd and Pb. After treating the ash obtained by dry combustion with a sufficient amount of acid, Fe, Cu, Mn, Zn and Mg were analyzed with atomic absorption spectrometry while Na and K were determined with flame photometry in feed samples. On the other hand Cd and Pb concentrations in the samples were also determined with atomic absorption spectrometry following microwave digestion procedure. Phosphorus amount in the samples were determined with a spectrophotometric method; calcium assay was performed by the titration method. Minerals that play an important role in the regulation of metabolic activities should be supplied to the animals in appropriate amounts. The acceptable maximum amount of Cd and Pb are indicated in related communique as 1 and 5 mg/kg respectively. The concentrations of Cd and Pb in our feed samples were determined below the limit values specified in the communique The required amount of minerals were given as minimum values for some elements and ranges for the others. These values for Fe, Cu, Mn, Zn, Mg, Na, K, Ca and P were >100 mg/kg, >10 mg/kg, >40 mg/kg, 40 mg/kg, >0,35%, %0,30-%0,50, >0,70%, >0,60%, %0,30-%0,50 respectively. The results of Fe, Cu, Mn, Zn, Mg, Na, K, Ca and P were 60 mg/kg, 52,51 mg/kg, 149,89 mg/kg, 224,24 mg/kg,%0,40, %0,59, %1,20, %1,27, %0,65 in feed sample (A); 257,15 mg/kg, 41,40 mg/kg, 138,54 mg/kg, 129,32 mg/kg,%0,45, %0,45, %1,18, %1,72, %0,77 in feed sample (B) and 52,84 mg/kg, 5,40mg/kg, 24,21 mg/kg, 29,57 mg/kg, %0,05, %0,05, %0,55, %0,72, %0,54 in feed sample (C) respectively. The results show that feed produced in factories around Manisa district meets the mineral requires of dairy cows while mineral contents of the self-produced feed were insufficient.