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Representative Results






Transition of Farm Pigs to Research Pigs using a Designated Checklist followed by Initiation of Clicker Training - a Refinement Initiative

Published: August 21st, 2021



1Department of Clinical Medicine, AUGUST Centre, Aarhus University
* These authors contributed equally

Refinement of porcine studies is achieved by introducing a standardized checklist and positive reinforcement training using a clicker. This work supports the collection of samples and the conduct of daily chores related to the animals.

Implementation of 3R initiatives is important. To refine the life of laboratory pigs, we focused on the time period prior to inclusion of animals in experiments. We improved the checklist during the development. By using the checklist each individual pig's progress was documented. This aids the caretakers so they remain focused on the actions necessary to socialize the animals and limit the animal's stress and anxiety level. During this phase, the pigs become calm and ready to commence additional clicker training to further limit stress during the experimental period. The pigs will readily allow basic outcome measures to be collected without sedation or fixation.

The protocol is divided in two. First the transition phase that begins as the pigs arrive at the research facility. Introducing treats and gradually closer contact to the caretakers are the first steps. Then, the caretaker introduces actions to be able to touch the head and hind, to mimic e.g. manipulating the ear to take a blood sample or the hind to obtain a rectal temperature. A strong foundation is established in the animal-caretaker relationship and this swiftly minimizes the stress the pigs express after arrival. Secondly, the positive reinforcement training commences to teach the animal how to carry out more complex tasks without becoming stressed. A clicker is introduced as a secondary reinforcer.

Time, structure, education and thorough communication seem to be the most important criteria to succeed in the application of this protocol. In addition to having calm and compliant pigs, the caretakers report that they enjoy the focus they are allowed to give each individual pig, adding to their overall job satisfaction. Having caretakers with a strong commitment, and a focus on the transition progress and welfare of each pig, additionally strengthens the department's Culture of Care.

The principles of the 3Rs (Replacement, Reduction and Refinement) discussed by Russell and Burch in 1959, form today's foundation for high ethical standards concerning the use of animals for experimental purposes. In biomedical research facilities engaged in preclinical laboratory animal studies, great importance must be adhered to the refinement principle. "Refinement means any decrease in the incidence or severity of inhumane procedures applied to those animals which still have to be used"1.

A contemporary definition additionally states that refinement is "advancing research into animal welfare by e....

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The pigs used to validate the protocol were part of studies approved by The Animal Experimental Council - a national governmental institution evaluating and approving all animal experiments in Denmark. The Council does the ethical review similar to an IACUC.

1. Arrival at the research facility

  1. First, wash the pigs in a designated area to allow a thorough visual inspection. Use an exclusion list to exclude pigs with wounds, ear bites, abscesses, lameness etc., so only animals that a.......

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Applying the transition phase as described in the protocol's part one allows for a smooth introduction of farm pigs to the research facility. Having calm pigs to work with eases daily chores and enables minor procedures and sample taking to be performed without anesthesia or fixation.

To follow the progress of pigs during the transition phase a checklist (Checklist 1) was developed to mark when individual pigs reach defined steps in their transition. The pigs are scheduled to enter researc.......

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The implementation of a protocol that includes part one, a transition phase checklist and part two, a consecutive clicker training program is a confirmed success. Introduction and use of a detailed checklist have provided a way to refine the introduction of pigs to the research facility. The structured transition phase furthermore creates a better foundation to train the pigs prior to inclusion in research projects. It has been a positive surprise to notice that the caretakers' commitment to the work increases and th.......

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Beatrice Tscherning Olesen, Karoline Jakobsen, Tine Bjørnholt Gustafsen, Helena Céline Kjær Byriel and Kira Sonnichsen Graahede are acknowledged for their great efforts, feedback and assistance in designing the checklist and using it in their daily work. Medical illustrator Ken Kragsfeldt is acknowledged for his professional help illustrating figure 3.


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Name Company Catalog Number Comments
Wrap, e-power, blå, 7,5cm E-vet A/S, Ole Rømers Vej 26 A, DK-6100 Haderslev 203165B Adhesive wrap used to wrap around the end of a stick to make a target stick. It is an advantage that it can be changed as it will get dirty quite quickly.
Apples Varius Uknown Used as treats
Klikker (Clicker) E-vet A/S, Ole Rømers Vej 26 A, DK-6100 Haderslev TX2289 Clicker used in training

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