Serum and Seminal Plasma Element Concentrations in Relation to Semen Quality in Duroc Boars.

Element concentrations in serum and seminal plasma were studied in Duroc boars with different semen quality characteristics. Based on the utilization rate of 2174 ejaculates from June to August in 2016, a total of 166 Duroc boars were allocated into three groups: low utilization rate group (LG, 0 to 60% utilization rate), medium utilization rate group (MG, 60 to 80%), and high utilization rate group (HG, 80 to 100%). Serum and seminal plasma samples were collected, and element levels were analyzed using inductively coupled plasma mass spectrometry. The results showed that LG boars had higher concentrations of serum copper and seminal plasma cadmium compared with MG and HG boars (P < 0.05), and serum copper and seminal plasma cadmium were negatively correlated with sperm motility, while positively correlated with the abnormal sperm rate. We observed the abnormal sperm rate increased by approximately 4.53% with serum copper increasing from 1.63 to 2.44 mg/L, while sperm motility decreased by approximately 2.85% with seminal plasma cadmium increasing from 0 to 0.82 μg/L. Moreover, serum iron and manganese levels in the LG group were significantly reduced compared with the HG boars (P < 0.05), and the two elements were negatively correlated with the abnormal sperm rate (P < 0.05). In conclusion, excessive copper and absence of iron and manganese in serum as well as higher seminal plasma cadmium may reduce the utilization rate of semen by impairing sperm motility and morphology, indicating the importance of adding and monitoring microelements in boar diet.