Competition for minerals (Zn, Mn, Fe, Cu) and Cd between sheep tapeworm (Moniezia expansa) and its definitive host sheep (Ovis aries)

Concentrations of various essential and toxic elements (Zn, Mn, Fe, Cu and Cd) were analysed by inductively coupled plasma optical emission spectrometry (ICP-OES) in the sheep tapeworm (Moniezia expansa) and in different tissues of its host Ovis aries. The element concentrations of the cestode parasites were compared to different organs (liver, kidney, and muscle) of sheep that were exposed to experimental amounts of Cd (0.2 g of CdCl2 added to 10 ml of distilled water and administered orally to the sheep every day for a period of 1 week). All sheep were randomly divided into four groups; the first group (Cd) contained uninfected, Cd exposed sheep, and its control (group C) were uninfected and unexposed to Cd; the second group (TCd) contained infected, Cd exposed sheep, and its control (group CT) contained infected, unexposed sheep. The experimental Cd exposure resulted in significantly higher Mn concentrations in sheep tapeworms (10.0 mg/kg) than in sheep muscle (0.6 mg/kg) and kidney (0.8 mg/kg). The experimental Cd exposure also significantly decreased the Cu concentrations in sheep liver and muscle. Moreover Cd exposure decreased the Fe concentrations in sheep kidney but caused it to increase in sheep liver and muscle. Zinc concentrations showed no differences between groups (Cd, TCd, C, T) in any monitored sheep tissues. The article also discuss the effect of tapeworm infection on a significant decrease of Fe in sheep muscle, liver and kidneys, as well as a decrease in Cu levels of the muscles and liver. This mineral imbalance may contribute to various health problems such as osteoporosis, metabolic processes disorder, antioxidant (SOD) dysfunction etc.