Impact of seaweed on growth performance, sperm quality, and testicular histomorphology of ram

Sperm quality is critical for male fertility, which is largely dependent on testicular development; however, nutrition is critical for optimal growth, gonadal development, and reproductive functions. This study aimed to investigate the effects of Gracilaria parvispora, a red seaweed on growth performance, testicular physiology, and semen quality in ram. Fifteen indigenous healthy rams, weighing 10-11 kg and aged 12-13 months, were randomly allocated into three groups. One group was considered as control and supplied with a German grass and concentrate mixture (control diet). The other two groups were provided with a control diet plus seaweed mixture at 7 g/d or 14 g/d. The starting body weight, scrotal circumferences, and semen quality of rams were similar for all groups. However, post-treatment, both the seaweed-treated groups showed significantly higher body weight, total weight gain, daily weight gain, and increased scrotal circumference and testicular dimensions, compared to the control group. Moreover, the semen parameters, including sperm concentration, live sperm percentage, mass motility, and progressive motility were observed to be significantly increased, while decreasing abnormal sperm percentage in the seaweed-treated group. Furthermore, DPPH and ABTS scavenging abilities of sperm and in vitro fertilization rate were increased dramatically in seaweed-treated groups. Additionally, the testicular histology of seaweed-treated groups revealed a thinner tunica albuginea with expanded seminiferous tubules containing a higher number of spermatogenic cells inside. These findings suggest that seaweed G. parvispora could be a valuable dietary supplement for enhancing the growth and reproductive performance of ram.