Chair training of non-human primates

Specifically designed restraint chairs are the preferred method of restraint for research studies that require non-human primates (NHPs) to sit in place for sustained periods of time. NHPs in the academic and government sectors spend a large part of their day, most days a week, in a restraint chair. It is important therefore to ensure that the restraint process is as fully refined as possible. Doing so will reduce any potential stress and keep discomfort to a minimum, ultimately facilitating good performance from the animal and high-quality scientific data.

Collaborating with researchers from the Yerkes National Primate Research Center at Emory University, the NC3Rs conducted an international survey of NHP chair restraint practices and identified opportunities for refinement.
 

Key recommendations

• Laboratories are encouraged to benchmark their practices against the survey results and these recommendations to determine how they might be modified to improve animal wellbeing and scientific quality.
• Researchers and animal care staff should keep themselves informed of published refinement techniques and make preferential use of the most humane training methods whenever possible.
• Before purchasing new chairs, laboratories new to chair restraint should consult with someone familiar with different styles of chairs and chairing procedures and review any recent refinements that might benefit the animals’ welfare and the outcome of the research. Commercially available chairs can be customised to improve comfort and choice for the animals and better meet training needs.
• Researchers using open chairs for restraint procedures should consider switching to the closed box chair – literature suggests this can improve training success, decrease training time and reduce animal stress. With the closed chair, an NHP can be trained to perform each of the steps necessary to voluntarily transfer from the home cage into the chair and to lift its head out of the opening of the chair without the use of pole-and-collar. The decrease in personnel time needed to prepare animals for restraint procedures and the accelerated pace of the science likely will more than recoup the expense of purchasing new chairs.
• Chair-training procedures should be based on operant conditioning and positive reinforcement, not merely passive habituation through repeated exposure. Where negative reinforcement is required, it should be used in combination with positive reinforcement. These techniques are recognized to be the best training methods for the safety of the animals and staff and for minimizing stress.
• Food and fluid restriction should not be necessary for chair restraint training.
• Laboratories should develop standard operating procedures to increase consistency in animal training, monitoring, and documentation of training efforts.
• Serious consideration should be given to employing dedicated animal trainers, who assume the major responsibility for all of the training of NHPs, or for training all staff who work directly with the animals. Providing such personnel can be a very powerful means of ensuring consistent and effective training practice, which can improve the research outcomes.
• Sufficient time should be allowed pre-study for chair training using positive reinforcement, which will help to minimise the effects of stress on study variables (e.g., enabling greater accuracy in detecting drug-induced changes in toxicology and safety pharmacology studies).
• Consideration should be given to introducing basic training techniques at the breeding or supplying establishment (i.e., before animals arrive at the research facility) or during quarantine periods prior to starting research procedures.
• Staff involved in chair restraint training should refresh their working knowledge of NHP behaviour, for example, by using the NC3Rs Macaque Website, attending relevant workshops or conferences, taking a class in NHP behaviour, and reading published literature.
• It is recommended to attend the NC3Rs-sponsored NHP restraint training workshop at the AALAS National Meeting.
• For animals showing regression (i.e., resisting and no longer cooperating with restraint procedures), provide additional time to train through the regression, or even breaks in research participation.
• Engaging an external consultant/animal behaviour specialist for outside of the laboratory/facility is recommended when chair restraint training is proving challenging – a new set of eyes on a training scenario may be able to provide a novel approach. Specialists can also provide tailored advice (e.g. on best practices, desensitisation to equipment, training protocols, animal temperaments) and are likely to give the most robust assessments of when NHPs are fully trained from the perspective of animal wellbeing.
• Research manuscripts should incorporate a brief description of the chair design and methods used to prepare animals for restraint procedures.
• Research studies of the following topics would be useful: formal comparisons of the effectiveness of PRT compared with NRT compared with a combination of both; identification of approaches most suitable for animals of a given temperament; assessment of automated approaches to animal training; and objective measures of stress or distress and how these states might affect the data being collected.

Read more about this project on our project page: Chair restraint training of non-human primates.