Supplemental Antibiotics in a Commercial Extender for Stallion Semen.

The study investigates the efficacy of adding antibiotic supplements to a commonly used semen extender for stallions, finding that one particular combination (amikacin disulfate and potassium penicillin G) is effective in reducing bacterial growth without negatively affecting sperm quality.

Objective of the Research

• The research aimed to ascertain the effects of adding supplemental antibiotics to a widely used semen extender (INRA 96) for stallions. The supplementary additives under investigation were amikacin disulfate and potassium penicillin G (combined as INRA-AP), as well as ticarcillin-clavulanate (INRA-TIM).

Methodology

• The researchers compared these two variations with the INRA 96 extender without any supplemental antibiotics (INRA-C). The semen was freshly extended and stored for observation.
• Sperm function (including sperm motion characteristics and plasma membrane intactness) and antibacterial activity were then observed at two time points: thirty minutes after extension (Time 30m) and twenty-four hours following cooled storage (Time 24h).

Findings

• Initially, there were no discernible differences among the three groups in terms of sperm motion characteristics or plasma membrane intactness. However, after twenty-four hours of cool storage, the INRA-AP group presented higher progressive motility and straightness compared to the INRA-C and INRA-TIM groups.
• The researchers also noted lower bacterial colony-forming units (CFUs) in the INRA-AP group at both time points. This group also showed a higher proportion of culture plates with no bacterial growth.
• The study indicates that adding the tested concentrations of amikacin disulfate and potassium penicillin G to the INRA 96 extender can successfully improve its antimicrobial activity without adversely affecting the quality of the sperm.