Effect of stage of gestation on the accumulation of copper, manganese, zinc, iron and calcium in fetal tissue of Awassi ewes in Northern Jordan

الملخص EN

The aim of this study was to monitor changes in concentrations of copper (Cu), manganese (Mn), zinc (Zn), and iron (Fe) and calcium (Ca) in fetal tissues of grazing Awassi ewes at different stages of gestation.

Liver, kidney and rib bone samples were collected from fetuses of Awassi ewes (n = 31), raised under extensive system, during routine slaughter operation at Irbid slaughterhouse in northern Jordan.

Fetal age was estimated by crown to rump length measurements.

Fetuses were grouped into three stages by age : stage 1, 30 to 50 days, stage 2, 51 to 100 days and stage 3, 101 to 150 days.

All samples were analyzed for Cu, Zn, Mn, Fe and Ca by atomic absorption spectrophotometry.

Copper and Zn concentration in fetal liver and kidney were significantly lower (P < 0.05) at late gestation than at early and mid-gestation, but liver Fe at late gestation, was significantly higher (P < 0.05) than at the first two stages.

There was no significant (P > 0.05) effect of fetal age on Mn concentration in liver and kidney, but Mn was significantly lower (P < 0.05) in fetal bones at early gestation than that at mid and late gestations.

Iron concentration in fetal rib bone was significantly high (P < 0.05) at early and mid-gestation and low at late gestation.

Liver Zn concentrations were positively correlated with kidney Cu (r = 0.56 ; P < 0.01).

Moreover, liver Ca concentrations were positively correlated with kidney Ca (r = 0.52 ; P < 0.05) and negatively correlated with kidney Fe (r = -0.45 ; P < 0.05).

Kidney Zn concentrations were positively correlated with kidney Fe (r = 0.52 ; P < 0.05).

Results indicate fetal storage of Cu and Zn in liver dropped with advancing gestational age as a result of high demand of these elements for fetal growth and development.