Effect of Glutamate Supplementation upon Semen Quality of Young Seasonally Sexual-Inactive Dorper Rams

The aim of this study was to determine if exogenous administration of glutamate to young Dorper rams is able to enhance semen quality under long-day photoperiods in northern Mexico (25° north). Dorper rams (n=10) with homogeneous live weight (LW; 56±0.9 kg), body condition score (BCS; 3.2±0.1 units) and scrotal circumference (SC; 31.9±0.38 cm) were randomly divided into two experimental groups and treated with: i) GLUT (n=5; 7 mg kg⁻¹ LW of glutamate, every 3d × 28d, im.) and ii) CONT (n=5; 1 mL of saline, every 3d × 28d, im.). At the end of the experimental period (d28), semen was collected throughout the use of an artificial vagina; different quality and quantity parameters were evaluated. The ANOVA reveled treatment differences (P<0.05) regarding sperm concentration with the largest value observed in the GLUT-rams (4, 260±95.9 × 10⁶ cells) regarding to the CONT-rams (2, 828±209.2 × 10⁶ cells). Yet, when considering the rest of the response variables which included ejaculation latency (47 ± 15.8 sec), seminal volume (1.1 ± 0.15 ml), total number of ejaculated sperms (4024.5 ± 696.5 × 10⁶ cells), mass motility (2.1 ± 0.3 units) and the percentage of sperms alive (57.5 ± 9.4%), no statistical differences (P>0.05) were observed between treatments. Results of this study unveils to glutamate as an interesting molecule positively affecting the spermatogenesis process by increasing the sperm concentration of young Dorper rams during photo-inhibitory reproductive schemes. Results also denote interesting outcomes not only to other animal industries but may also embrace translational applications.