Effects of adding different levels of Glutamine to modified Beltsville extender on the survival of frozen rooster semen

- Glutamine improve the quality of rooster frozen semen.
- Lower doses of glutamine in rooster extender was more effective in maintaining sperm quality and morphology.
- It is possible to use glutamine for long-term freezing of rooster sperm.

The aim of the present study was to investigate the effects of l-glutamine on the quality of frozen-thawed rooster semen. Semen samples were collected from eight mature roosters (Ross 308). After initial semen assessments, samples of adequate quality were mixed together and diluted with modified Beltsville extender without l-glutamine (control) and supplemented with 2.5, 5, and 7.5 mM l-glutamine. Semen straws were subjected to cryopreservation and evaluated twice at 15-day intervals. After thawing, sperm viability, total and progressive sperm motilities were measured by Eosin-Nigrosine and Computer-Aided Sperm Analysis (CASA), respectively. The results showed that sperm functions decreased on day 30 compared to day 15. The extender supplemented with 5 mM glutamine improved (p < 0.05) sperm viability, total and progressive sperm motilities compared to other treatments and the control group. The best level of glutamine appeared to be 2.5 mM, as it provided the highest sperm membrane integrity and the lowest level of abnormalities. The results of this study suggest that the addition of glutamine to the diluent improves semen quality and using glutamine allows rooster sperm to be frozen for longer.