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

Collaborative semen collection in monkeys is a valuable tool in research, animal collection management, and conservation efforts. To obtain samples, monkeys are often restrained in open restraint chairs (ORC) with the “pole and collar” technique. While commonly used, this restraint is not tolerated...

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Bibliographic Details
Main Authors: Lisa A. Houser, Cathy Ramsey, Fernanda M. de Carvalho, Breanna Kolwitz, Chelsey Naito, Kristine Coleman, Carol B. Hanna
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Animals
Subjects:
Online Access:https://www.mdpi.com/2076-2615/11/8/2384
Description
Summary:Collaborative semen collection in monkeys is a valuable tool in research, animal collection management, and conservation efforts. To obtain samples, monkeys are often restrained in open restraint chairs (ORC) with the “pole and collar” technique. While commonly used, this restraint is not tolerated by all individuals; some become anxious or aggressive towards the poles and people. In an effort to refine this procedure and improve welfare of the monkeys, we examined the use of a “closed box chair” (CBC), a clear, plexiglass box in which the monkey is trained to sit for sperm collection. The CBC does not require pole and collar, and although legs are secured, the arms and neck are not restrained. The use of CBCs has increased in recent years; however, there are few studies demonstrating its effects on scientific outcomes. We used positive reinforcement techniques to train 34 adult male rhesus macaques (<i>Macaca mulatta</i>) to provide semen samples using either the ORC or the CBC. While all CBC monkeys (<i>n</i> = 14) were reliably trained for this procedure, only 75% of ORC (<i>n</i> = 20) males completed the training (<i>p</i> = 0.04). It took significantly less time to train animals in the CBC than the ORC (201.0 vs. 412.4 min; <i>p</i> <0.001). In a controlled subset, males restrained with ORC (<i>n</i> = 7) produced a significantly lower ejaculatory volume than those collected by CBC (<i>n</i> = 10) (297.6 µL vs. 522.1 µL respectively; <i>p</i> = 0.04) and had a lower concentration of sperm (186.0 × 10<sup>6</sup>/mL vs. 367.5 × 10<sup>6</sup>/mL respectively; <i>p</i> = 0.017), although there were no differences with respect to sperm motility (<i>p</i> = 0.15). Our data suggest the closed box chair technique reduces stress on the animals while enhancing semen quality, supporting the use of the CBC as an important refinement.
ISSN:2076-2615