Ostrich ejaculate characteristics and male libido around equinox and solstice dates

Abstract

The study evaluated the effect of time of the year in which changes in photoperiod occurs on ostrich semen characteristics and male libido. Semen was collected for five days before, on and five days after winter solstice (21 st June 2016), spring equinox (22 nd September 2016), summer solstice (21 st December 2016) and autumn equinox (20 th March 2017) in the southern hemisphere. Semen was collected from 10 South African Black ostrich males (average age ± standard deviation: 4.5 ± 2.27 years) using the dummy female. Semen volume, sperm concentration, total sperm per ejaculate, sperm motility traits, percentage of normal sperm, head and tail abnormalities and percentage of affected sperm in the hypo-osmotic swelling test (HOS) were evaluated. Male libido defined as the willingness of males to mount the dummy female was also recorded. Semen samples collected around summer solstice, spring and autumn equinox were higher in sperm concentration and sperm output compared to winter solstice (P < 0.05). Study periods did not influence semen volume, sperm motility traits, the percentage of normal sperm, head abnormalities and HOS. Tail abnormalities were higher around winter solstice than around spring equinox (P < 0.05). Male libido and the success of semen collection were significantly higher around spring equinox (P < 0.05). Changes in photoperiod in the southern hemisphere do not affect semen production in ostriches. However, high sperm output and male libido around spring equinox 2 and summer solstice dates suggest that these periods may be preferred for semen collection for artificial insemination and storage purposes.

Extreme temperatures compromise male and female fertility in a large desert bird

“…Only males from which we were able to obtain at least five ejaculates were included in the analysis to avoid including males not accustomed to the ejaculation collection process. Subsets of these data have previously been used to test effects of season, age and collectio [78][79][80] .…”