Live cells are not affected by dead sperm in liquid boar semen: New insights based on a thermo‐resistance test

This study evaluated the effect of different proportions of dead spermatozoa on the quality of liquid boar semen during a thermo‐resistance test (TRT). After 3 days of storage (17°C), 54 conventional artificial insemination semen doses (~23 × 106 sperm/ml in ~88 ml of BTS) were split into three 15 ml‐treatments (25%, 50%, and 75% dead sperm cells) by mixing two subsamples containing 75% (I) and 0% (II) of live cells. Spermatozoa were evaluated after TRT at 30 (on‐test) and 300 min (off‐test) incubation at 38°C. At the on‐test, treatments of 25%, 50%, and 75% dead sperm cells showed medians for total sperm motility of 77.6%, 50.2%, and 25.6%, respectively. Considering the absolute variation of sperm motility during TRT, doses with 25% dead sperm lost more percentage points (pp) (−9.4 pp) compared to doses containing 50% (−8.2 pp) and 75% dead sperm (−4.5 pp). The lowest loss was observed for doses with 75% dead sperm (p