| dc.description.abstract | This study aimed to assess the influence of different concentrations of zinc (Zn),
lead (Pb), mercury (Hg) and cadmium (Cd) found in the feed and water provided
to bulls on the concentrations of these metals in cryopreserved bull semen, and to
determine their influence onto semen quality parameters. Correlations between heavy
metal concentrations in the semen and the quality parameters of semen as estimated
by computer-assisted sperm analysis (CASA) and flow cytometry (FC) methods were
determined.
A total of 40 cryopreserved semen samples originating from bulls housed in 4 different
centers for artificial insemination (A, B, C and D) were examined, making a total
of 160 samples. The concentrations of metals and semen quality parameters were
determined in cryopreserved semen of 10 bulls from each center, namely 4 samples
from each bull. Concentrations of Zn, Pb, Hg and Cd in hay and concentrated feed
were within the allowed limits as proposed by the National Research Council (NRC,
2000). A strong negative correlation was detected between curvilinear velocity (VCL)
and Zn concentrations in the semen (P < 0.01; r = -0.772) in group D, and a positive
correlation of VCL with Pb concentrations (P < 0.05 and r = 0.718) in group B.
Mercury concentrations in cryopreserved semen correlated negatively to the percent of
live sperm cells with intact acrosomes (V/IA: P < 0.05; r = -0.640) and positively with
the percent of dead sperm cells with damaged acrosomes (D/DA: P < 0.01; r = 0.766)
in group D. This finding confirms the hypothesis that Hg, even at low concentrations,
may cause acrosome damage. | en_US |
