Sperm DNA fragmentation and morphological degeneration in chilled elephant (Elephas maximus and Loxodonta Africana) semen collected by transrectal massage

Authors

  • J. K. O'Brien,

    Corresponding author
    1. Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia
    • Sea World and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, CA, USA
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  • K. J. Steinman,

    1. Sea World and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, CA, USA
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  • G. A. Montano,

    1. Sea World and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, CA, USA
    2. Department of Animal Science, Texas A&M University, College Station, TX, USA
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  • C. C. Love,

    1. Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
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  • T. R. Robeck

    1. Sea World and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, CA, USA
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Correspondence:

Justine K. O'Brien, SeaWorld and Busch Gardens Reproductive Research Center, 2595 Ingraham St, San Diego, CA 92109, USA. E-mail: justine.obrien@seaworld.com

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 of DNA damage (64.2 ± 19.2% fragmented DNA) and an elevated incidence of detached heads (43.3 ± 22.5%). In contrast, good quality ejaculates designated as those with >50% TM at 24 h displayed higher (< 0.05) values of sperm kinetic parameters, DNA integrity 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 considerable DNA damage 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.

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