TNF and infection: Within the heterogeneous group of pro-inflammatory molecules, TNF-α, IL-1, and IL-6, which are primarily secreted during infection, may promote the loss of membrane integrity, phosphatidylserine translocation, and subsequent cell death [56], which corresponds with their increasing levels proportionately to a decreased semen quality as observed in this study as well as in previous reports on stud animals [18,24,39].