Volume 75 (2025) Issue: 2025 No#3

Changes in the concentrations of heavy metals in goat blood during the first third of the lactation period

Author(s): Zvonko Antunović, Željka Klir Šalavardić, Boro Mioč, Josip Novoselec

Keywords:blood; elements; environment; goats; lactation

The changes in the concentrations of heavy metals in the goat blood throughout the first three months of lactation were the studied objective of the present paper. The experiment was carried out on 20 French-Alpine goats, aged five years and in their 4th lactation. The tested goats were examined on the 30th and 90th day of lactation. The concentrations of the following heavy metals: Cd, Pb, Cr, Ni, As and Hg, were determined in the feed and serum by inductively coupled plasma mass spectrometry. The GLM procedure was used to analyze the impact of the blood sampling time on the concentration of heavy metals. Morning milk yield of goats was lower (p=0.033) on the 90th day of lactation compared to the 30th day (1.29 vs. 1.69 kg). Compared to the first sampling of blood on the 30th day (As=3.61 and Cd=1.85 µg/kg, p<0.001), this experiment proves a significant decrease in concentrations of As and Cd in goat blood sampled during the second run, on the 90th day (As=1.73 and Cd=0.66 µg/kg, p<0.001). In the blood samples the concentration of Ni has decreased on the 90th day (6.51 vs. 2.39 µg/kg, p=0.013) by 63%. Positive correlations between Cr:Ni (r=0.47, p=0.011) and Ni:Hg (r=0.55, p=0.002) and a negative correlation between As:Pb (-0.40, p=0.028) in the blood were determined in the first third of the lactation period. The concentration of heavy metals in the goat blood measured in the present study were within the reference range, which implies a well-preserved environment in which the goats were reared.