Field-Compatible Cytometric Assessment of Epididymal Alpaca Sperm Viability and Acrosomal Integrity Using...

Area of Science:

• Reproductive Biology
• Animal Science
• Biotechnology

Background:

• Limited access to advanced laboratories in remote alpaca breeding regions hinders sperm analysis.
• Effective sperm quality assessment is crucial for successful alpaca breeding programs.

Purpose of the Study:

• To validate a practical flow cytometric method for evaluating epididymal alpaca sperm viability and acrosomal integrity.
• To assess the feasibility of intermediate storage of fixed sperm samples for later analysis.

Main Methods:

• Epididymal spermatozoa were collected from 26 alpaca testes.
• Sperm samples were stained with Zombie Green (viability) and FITC-PSA (acrosomal integrity).
• Cytometric analysis was performed immediately (T0), 24 hours post-fixation (T24), and 1 week post-fixation (T1w).

Main Results:

• Fixed samples (T24 and T1w) showed higher viability (approx. 71%) and acrosomal integrity (approx. 97%) compared to immediate analysis (T0: 67.6% viability, 95.9% integrity).
• Strong correlations and Bland-Altman analysis confirmed consistency across all time points.
• The method demonstrated reliability for sperm quality evaluation up to one week after collection.

Conclusions:

• The validated flow cytometric method provides accurate assessment of alpaca sperm viability and acrosomal integrity.
• This technique is suitable for reproductive monitoring in field conditions, overcoming limitations of immediate laboratory access.
• Further research should explore its application with ejaculated semen and optimize field protocols.