Improved Training and Semen Collection Outcomes Using the Closed Box Chair for Macaques

Area of Science:

• Primate reproductive biology
• Animal welfare science
• Conservation science

Background:

• Semen collection in non-human primates is crucial for research, management, and conservation.
• The traditional open restraint chair (ORC) with pole and collar can cause stress and anxiety in some individuals.
• Refining restraint techniques is essential for improving animal welfare during sample collection.

Purpose of the Study:

• To compare the efficacy and animal welfare outcomes of the closed box chair (CBC) versus the open restraint chair (ORC) for semen collection in rhesus macaques.
• To evaluate the impact of restraint method on training success, training time, and semen quality parameters.

Main Methods:

• Thirty-four adult male rhesus macaques were trained using positive reinforcement to provide semen samples via either ORC or CBC.
• Training success rates and time to train were recorded for both methods.
• Ejaculatory volume, sperm concentration, and sperm motility were compared between males sampled using ORC and CBC.

Main Results:

• Training success was significantly higher in the CBC group (100%) compared to the ORC group (75%) (p=0.04).
• Training time was significantly shorter for the CBC method (201.0 min) than the ORC method (412.4 min) (p<0.001).
• Males collected via CBC yielded significantly higher ejaculatory volume (522.1 µL vs. 297.6 µL; p=0.04) and sperm concentration (367.5 × 10^6/mL vs. 186.0 × 10^6/mL; p=0.017) than those collected via ORC.

Conclusions:

• The closed box chair (CBC) method is a more efficient and effective technique for training and semen collection in rhesus macaques.
• The CBC reduces animal stress and enhances key semen quality parameters, supporting its use as a welfare refinement.
• This refined technique has significant implications for improving animal welfare and data quality in primate research and conservation programs.