Abstract:This study investigated the effects of UV irradiation on sperm motility and duration of sperm activity and determined the optimal UV irradiation dosage to genetically inactivate sperm, while retaining adequate motility to fertilize eggs. Milt from several males was diluted 1:30 with Ringer's solution and UV irradiated at an intensity of 2200 μW/(cm2·s), and used to fertilize eggs. The fertilized eggs were divided into a cold-shock group (3℃ for 10 min at 2 min 30 s after fertilization) and a control group without cold-shock. Early embryo survival rate and larvae hatching rate were measured and compared. The results showed that:1) motility of sperm was negatively correlated with UV treatment time, and the rapid changes in sperm showed a typical Hertwig effect; 2) early embryo survival rate induced by sperm in the control groups was negatively correlated with the UV exposure time, while the larvae hatching rate showed a typical Hertwig effect; 3) early embryo survival rate and larvae hatching rate induced by sperm in the cold-shock group showed a typical Hertwig effect with the increase in UV irradiation time, reaching peaks at 2 min 20 s and 1 min 30 s, respectively (the peak values of the survival and hatching rates of were (38.3±4.3)% and (66.5±5.1)%, respectively; the peak values of the survival and hatching rates of were (43.3±3.3)% and (67.7±6.3)%, respectively). The results of this study indicated that the optimal UV dosages for eggs were 308 mJ/cm2 and 198 mJ/cm2, respectively. These results provide information for the improvement of gynogenetic technology for .