Chitosan-Based Semen Extenders: An Approach to Antibiotic-Free Artificial Insemination in Rabbit.

Area of Science:

• Animal Science
• Veterinary Medicine
• Microbiology

Background:

• Antibiotic use in livestock contributes to antimicrobial resistance, necessitating alternatives.
• Chelating agents like EDTA and Chitosan may reduce bacterial contamination in semen doses for artificial insemination (AI).
• Preserving sperm quality during liquid storage is crucial for AI success.

Purpose of the Study:

• To evaluate ethylenediaminetetraacetic acid (EDTA) and Chitosan as antibiotic alternatives for liquid storage of rabbit AI semen doses.
• To assess their efficacy in maintaining sperm quality and controlling bacterial contamination.
• To compare their impact on fertility and kit production post-storage.

Main Methods:

• Rabbit semen extenders were formulated with EDTA (20 mM), Chitosan (0.05%), their combination, antibiotics, or none.
• Antimicrobial efficacy was tested against Enterococcus faecalis.
• Sperm quality was assessed in vitro during 72-hour refrigeration (16 ± 1 °C).
• Fertility and kit born were evaluated after 24-hour storage under commercial AI conditions.

Main Results:

• 0.05% Chitosan in extenders yielded sperm parameters and bacterial load similar to antibiotics.
• Chitosan-treated semen showed comparable fertility rates and kit born outcomes to antibiotic-treated semen after 24-hour storage.
• EDTA (alone or combined with Chitosan) was less effective against Enterococcus faecalis than antibiotics.
• EDTA negatively impacted sperm motility, fertility, and kit born outcomes.

Conclusions:

• Chitosan demonstrates significant antimicrobial activity and protective effects on sperm function.
• Chitosan is a viable alternative to antibiotics for liquid storage of rabbit AI semen doses.
• Further research may explore optimized Chitosan concentrations and combinations for enhanced semen preservation.