Abstract
Summary
Ejaculates from nine Asian and two African elephants were analysed to gain a further understanding of mechanisms underlying variable semen quality after transrectal massage. Semen analysis was performed after collection (0 h; subjective motility parameters only) and after 24 h of chilled storage at 10 °C (24 h; all ejaculate and sperm characteristics). Ejaculates with ≤50% total motility (TM) at 24 h, which represented >90% of collection attempts, contained a sperm population with a high degree ofDNAdamage (64.2 ± 19.2% fragmentedDNA) and an elevated incidence of detached heads (43.3 ± 22.5%). In contrast, good quality ejaculates designated as those with >50%TMat 24 h displayed higher (p DNAintegrity and normal morphology. Fertility potential was high for good quality ejaculates from two males (one Asian and one African bull) based on in vitro characteristics after chilled storage for up to 48 h post‐collection. Urine contamination of semen, as assessed quantitatively by creatinine concentration, was confirmed as a significant factor in reduced elephant ejaculate quality. However, the identification of considerableDNAdamage and morphological degeneration in the majority of ejaculates after only 24 h of chilled storage indicates that sperm ageing could be a primary contributor to inconsistent semen quality in the elephant.