Dietary supplementation with rosemary essential oil improves genital characteristics, semen parameters and testosterone concentration in Barki rams

Abstract Background Male reproductive performance is an essential part of sheep production; therefore, the use of natural antioxidants to improve sperm quality and maintain reproductive performance in males is very important. Hence, oral administration of rosemary essential oil (REO) was investigated to improve the fertility rate, including the ultrasonographic testes, epididymal tail and genital glands, as well as semen parameters and testosterone concentration. Sixty animals were splitted into two groups, each with 30 rams; the rosemary group (C + REO) received 2 mg/kg/bw and the control group (C-REO). Ultrasound images and blood samples were collected at 15, 30 and 45 days of the REO treatment. Results The testis and epididymal tail ultrasonographic assessments demonstrated a significant enhancement in the C + REO group compared to the C-REO group. However, the rams in the C + REO group showed significant improvements in the pampini-form plexus, seminal vesicle, Cowper's and prostate genital glands compared to the C-REO group. The data showed that the sperm cell concentration (× 109/ml) and individual motility (%) were significantly improved in the C + REO group. Furthermore, ejaculate volume (ml) in the C + REO group was significantly higher than that in the C-REO group. While the animals treated with REO did not improve live spermatozoa (%), it reduced the abnormalities of spermatozoa (%) compared to the C-REO group. Also, the C + REO group significantly increased the testosterone concentration more than the C-REO group. Conclusion It can be concluded that supplementation with 2 mg/kg/bw REO improves genital characteristics, semen parameters and testosterone concentration in Barki rams.