Semen characterization, seasonality of production, and in vitro sperm quality after chilled storage and cryopreservation in the king penguin ( Aptenodytes patagonicus )

Research was conducted to examine seasonal seminal traits and to establish short‐term and long‐term sperm preservation methods in the king penguin ( Aptenodytes patagonicus ) for use in genome banking and artificial insemination (AI). Spermic ejaculates ( n  = 87) obtained using a cooperative method were collected across multiple ( n  = 6, Male 1) and a single (Male 2) breeding season(s). Non‐contaminated ejaculates ( n  = 69) were 0.36 ± 0.32 ml at 56.3 ± 62.7 × 10 7  sperm/ml with 85.3 ± 10.6% total motility (TMot), 52.5 ± 12.9% progressive motility (PMot), 86.6 ± 24.3 µm/sec average path velocity (VAP) and 92.3 ± 3.7% plasma membrane intact. In vitro quality of chilled semen was best maintained over 48 hr at 5°C than 21°C, with decreased ( P  < 0.05) motility and morphology parameters observed by 24 and 6 hr, respectively. A comparison of two freezing methods (straw [STR] vs. directional [DF]) demonstrated similar effects on post‐thaw quality at 0 and 3 hr, with the exception of plasma membrane integrity which was higher ( P  < 0.05) at 0 hr for DF (48.7 ± 6.5%) than STR (41.2 ± 7.0%). At 0 hr post‐thaw, DF samples retained 46%, 69%, and 52% of their initial PMot, VAP, and plasma membrane integrity, respectively. Normal morphology of motile cells was reduced ( P  < 0.05) during freeze–thawing from 84% post‐collection to 37% and 34% at 0 and 3 hr post‐thaw, respectively. Results indicate that chilled and cryopreserved semen from the king penguin has potential for use in AI. Zoo Biol. 33:99–109, 2014. © 2014 Wiley Periodicals Inc.