Effect of age on quality of fresh and frozen-thawed semen in White Italian ganders.

ABSTRACT

AIM: To comparatively evaluate the fresh semen quality of 1, 2 and 3-yr-old White Italian ganders (Anser anser L.) and the susceptibility of spermatozoa to freezing-thawing procedure. METHODS: Semen was collected by dorso-abdominal massage every 2 days~3 days from three groups of ganders 1-yr-old (n=11), 2-yr-old (n=7) and 3-yr-old (n=9). In the pooled fresh semen samples, the following parameters were evaluated the ejaculate volume, the blood or feca contamination and the motility, concentration and morphology of spermatozoa. Sperm motility and morphology were evaluated in the frozen-thawed semen. Semen diluted with EK extender was frozen in straws in a computerized freezing unit with 6 % dimethyl-formamide to -140 deg at a rate 60 deg/min and then transferred into the LN2 container. Straws with semen were thawed in a water bath at 60 deg. RESULTS: The ejaculate volume decreased with the age (0.21 mL for 1-yr-old, 0.18 mL for 2-yr-old and 0.14 mL for 3-yr-old ganders); the sperm concentration increased with the age (327 x 10(6) mL(-1) for 1-yr-old, 431 x 10(6) mL(-1) for 2-yr-old and 547x10(6) mL(-1) for 3-yr-old ganders); the number of live - normal sperm was significantly (P<0.01) lower in the 1-yr-old than that in the 2- and 3-yr-old ganders (26.61 %, 41.54 and 35.9 %, respectively). The percentage of normal cells survived the freezing-thawing process was 37.7 %, 43.3 % and 40.9 % for 1-, 2- and 3-yr-old ganders, respectively. CONCLUSION: Freezing and thawing processes more significantly (P<0.01) affected the motility, viability and morphology of spermatozoa in semen of 1-yr-old ganders in comparison with older males.