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 5 days before, on and 5 days after winter solstice (21 June 2016), spring equinox (22 September 2016), summer solstice (21 December 2016) and autumn equinox (20 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 with 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 and summer solstice dates suggest that these periods may be preferred for semen collection for artificial insemination and storage purposes.

该研究评估了一年中不同时期的光周期变化对鸵鸟精液特性和男性性欲的影响。在南半球冬至（2016年6月21日），春分（2016年9月22日），夏至（2016年12月21日）和秋分（2017年3月20日）之前，之后和5天收集精液。使用假女性从10只南非黑鸵鸟雄性中收集精液（平均年龄±标准差； 4.5±2.27岁）。在低渗溶胀试验（HOS）中评估精液量，精子浓度，每次射精的总精子量，精子运动性状，正常精子百分比，头尾异常以及受影响的精子百分比。男性性欲也定义为男性愿意安装假女性的性欲。P  <0.05）。研究期不影响精液量，精子运动性状，正常精子百分率，头部异常和HOS。冬至前后的尾部异常高于春分前后（P  <0.05）。春季春分前后，男性性欲和精液收集成功率显着更高（P  <0.05）。南半球光周期的变化不会影响鸵鸟精液的产生。然而，高精子产量和春分和夏至日前后的男性性欲暗示，这些时期对于人工授精和储存目的的精液收集可能是优选的。