The aim of this research was to determine serum and liver concentrations of Cu, Mo, Fe and Zn in sheep and goats slaughtered in the semiarid region of the state of Pernambuco, northeastern Brazil, during the rainy and dry seasons, and to establish if Cu deficiency which occurs in the region is primary or secondary to high levels of Mo and/or Fe. Serum and liver samples from 141 goats and 141 sheep were submitted to wet digestion in nitric-perchloric acid and analyzed by coupled plasma atomic absorption spectrophotometry (ICPOES). The mean serum concentrations of Cu were 9.85±2.71µmol/L in sheep and 11.37±2.57µmol/L in goats. Mean Cu liver concentrations were 158.45±83.05mg/kg in sheep and 152.46±79.58mg/ kg in goats. Mean serum concentrations of Fe were 35.58±14.89µmol/L in sheep and 25.06±8.10µmol/L in goats. Mean liver concentrations of Fe were 156.10±55.99mg/kg in sheep and 210.53±121.99mg/kg in goats. Mean serum concentrations of Mo were 0.28±0.11µmol/L in goats and 0.31±0.16µmol/L in sheep. Mean liver concentrations of Mo were 6.53±4.13mg/kg in goats and 8.10±4.01mg/kg in sheep. Mean serum concentrations of Zn were 11.9±6.07µmol/L in sheep and 11.79±7.42µmol/L in goats. Mean liver concentrations of Zn were 126.43±51.50mg/kg in sheep and 132.91±55.28mg/kg in goats. Based on Cu serum and liver concentrations and on the sporadic occurrence of enzootic ataxia, Cu supplementation is recommended for grazing sheep and goats during the dry and the rainy seasons. Considering that serum and hepatic concentrations of Fe and Mo are within normal ranges or are marginal, it is suggested that the low Cu concentrations are not related with high Fe or Mo ingestion. Non significant differences were observed between serum and liver concentrations of Cu and Mo, and between serum concentrations of Fe in samples collected during the rainy season and the dry season. Liver concentrations of Fe and serum and liver concentrations of Zn were significantly higher during the rainy season. Taking into account that serum and liver Zn concentrations in sheep and goats are considered marginal, supplementation with Zn is suggested for grazing sheep and goats, mainly during the dry season.
Microelements; ruminants; blood; liver; copper deficiency; zinc deficiency; mineral deficiency
