Exploring the relationship between blood serum macro and micro minerals and sperm quality characteristics in fresh and frozen-thawed bulls’ semen

One interesting topic in reproductive biology is to explore the correlations between minerals and male fertility. The aim of the present study was to investigate the relationships between Calcium (Ca), Magnesium (Mg), Zinc (Zn), Copper (Cu), and Iron (Fe) and their associations with semen quality in bulls.

Ejaculates were collected from Simmental bulls. Semen quality parameters including volume, concentration, motility, sperm viability and morphology were assessed. One step dilution method was utilized for semen freezing. Progressive motility of frozen-thawed semen (PMFT) was regarded as the main criterion for dividing data into three groups: group 1 (˂ 40% motility), group 2 (40% -50% motility), and group 3 (> 50% motility). Serum mineral concentrations were determined by atomic absorption. The Serum Fe was significantly lower in “> 50%” group compared with other groups.

Semen volume was negatively correlated with PMFT (r = -0.42, p ≤ 0.05 and serum Fe (r = 0.44, p ≤ 0.05). Negative correlations were found between Zn to Cu ratio with frozen-thawed sperm abnormal morphology (r = -0.43, p ≤ 0.05) and tail abnormality and fresh sperm mid-piece abnormality(r= 0.47, p ≤ 0.05). There was also a negative correlation between Zn and frozenthawed sperm head abnormality (r= -0.57, p ≤ 0.05).

With regard to the weak positive correlations between serum Cu and frozen-thawed sperm tail abnormal morphology, it can be concluded that the excess of serum Cu may have destructive effects on normal sperm morphology.