Injecting the peptide kisspeptin-10 once a week for a month boosted semen volume, sperm count, live sperm percentage, and testosterone levels in young male sheep, and it also made the sperm swim better in a flow test.

The aim of the present study was to investigate the effect of kisspeptin-10 (Kp10) injection on semen characteristics, testosterone (T) production and sperm rheotaxis using microfluidic devices in immature ram. Computer-assisted sperm analysis (CASA) with controlled flow velocity was used to explore the kinetic parameters of sperm and positive rheotaxis (PR %). PR % was defined as the number of PR sperms over the number of motile sperms. Healthy Ossimi rams were randomly divided into two groups; a saline-treated control group and Kp10-treated one (5 µg/kg body weight). Treatments were given by intramuscular injection once a week for 1 month. After 1 month, the semen was collected and evaluated weekly for 6 weeks, while the blood samples were collected every 2 weeks for the next 8 weeks. Semen properties were significantly affected by Kp10 injection (p < .01). The Kp10 increased the volume, sperm concentration and percentages of live sperm compared with those of control. Additionally, sperm trajectories and rheotaxis get improved by the injection of Kp10 with time. Furthermore, kisspeptin improved the secretion of testosterone levels throughout the period of study. In conclusion, injections of the Kp10 had a positive impact on semen characteristics as well as improved sperm rheotaxis of Ossimi rams in subtropics.