The impact of iron and manganese concentration in water and feed on their presence in tissues of fattening bullocks

Abstract

From January to June 2011 the content of iron and manganese in water, hay, complete feeds and muscular tissue, liver and kidneys of fattening bullocks after slaughtering was monitored with the aim of determining the correlation between the concentration of these elements in tissues and their quantity in water and complete feeds. The bullocks were bred on a mini farm in Kraljevo. Water and hay samples were collected on a fifteen-day basis. Ten samples of water, hay, complete feeds, muscular tissue, liver and kidneys were processed. Apart from water, all the samples for the analysis were prepared by dry ashing and decomposition in a microwave oven (simultaneously), while Mn and Fe were determined by atomic absorption spectroscopy (AAS) (AOAC 1990). The method of sample preparation did not affect the values of obtained results. The average quantity of iron in water amounted 1.92 mg/L, 185.52 mg/kg in hay, 137.43 mg/kg in complete feeds, 38.87 mg/kg in muscular tissue, 67.60 mg/kg in liver and 78.83 mg/kg in kidneys. The average content of manganese was 1.57 × 10-2 mg/L in water, 76.01 mg/kg in hay, 12.64 mg/kg in complete feeds, 0.34 mg/kg in muscular tissue, 2.37 mg/kg in liver and 1.12 mg/kg in kidneys. Our results showed that the intake of iron through water was significantly above MAC (maximum allowable concentration), whereas the quantity of manganese was substantially lower. The determined quantity of Fe in complete feeds was above minimal needs of bullocks as opposed to the quantity of Mn that did not comply with the proscribed limited quantity. The highest content of iron was determined in kidneys, and manganese had the highest value in bullocks liver.