Colla-boar-ation: Teaching Pigs to Participate in their Own Care using Positive Reinforcement Training Methods
By Martyna Abbatello
Laboratory Animal Resource
Part of my identity as an animal caregiver is animal training. It runs through my veins. It’s the perfect choice to facilitate difficult husbandry tasks. I worked in the zoo field for 17 years, where I lived and breathed training. When the opportunity to exercise this knowledge presented itself at my new lab job, I couldn’t resist.
Within 3 months of starting at my current facility, an upcoming survival study was scheduled that would use pigs as the animal model. Post-surgical data collection had previously been difficult to collect. In these studies, animals seemed hesitant of physical touch interactions with staff, specifically rectal temperature readings. The staff and animals’ relationships were primary focused on daily husbandry, loading them into transport cages for weights or surgery transport, and providing food and toys as enrichment. When time came to perform post-surgical temperature, pulse and respiratory rate (TPR), they were hesitant to cooperate. I recognized this was due to lack of physical touch with the staff, and training would be a great solution to mitigate this and gain trust.
I wrote out a basic training outline, demonstrating the timeframe from arrival until surgery. Additionally, I created a presentation for the staff on basic animal training. We had several weeks before the animals would arrive, and therefore had time to practice on other animals in the facility.
The training plan had nine approximations, physical interaction being the first step. Physical interaction is an important training step, as it gets the animals used to our presence and gains our trust. The last step was the animal standing still at a target with one trainer, while the second trainer completes the procedure. Below are the approximations we used:
- Animal responds calmly to positive human interaction (PHI) and is reinforced with apple juice after a short whistle sound. This sound will be used to bridge behavior cues with proper execution of behavior.
- Tech presents animal with fist near their nose. When animal touches fist, say the command “target.” Reinforce with apple juice after bridge.
- Animal performs TARGET behavior after tech says “target”. Reinforce after bridge for proper execution of behavior. Move further away each subsequent time and/or move your fist to varying heights to encourage animal to touch.
- Animal performs TARGET behavior. While standing still at the target, tech 1 says “hold”. Bridge and reinforce for standing still while touching target. Each subsequent time, increase the duration of HOLD before bridging and reinforcing with apple juice.
- Animal responds calmly to presence of thermometer, stethoscope, and techs in and outside of pen. Reinforce calm behavior.
- Animal performs TARGET and HOLD behaviors for tech 1. Tech 2 touches animal with thermometer near the rump and with stethoscope on chest. Tech 2 will indicate to Tech 1 when to bridge. Increase length each subsequent time. Tech 1 reinforces with apple juice.
- Animal performs TARGET and HOLD for Tech 1, Tech 2 checks pulse with stethoscope. Tech 1 bridges after desired result indicated by Tech 2. Increase duration of procedure each subsequent time. Bridge after completion of each increment of time and reinforce with apple juice.
- Animal performs TARGET and HOLD for Tech 1, Tech 2 inserts thermometer slowly into rectum. Tech 1 will bridge after desired duration indicated by Tech 2. Only insert a few centimeters for a few seconds at a time until desired depth and duration is achieved.
- Tech 2 completes both parts of procedure, pulse followed by temperature, while standing still at the target for tech 1. Animal is reinforced during the duration of the procedure for proper execution of behavior.
It is important to mention that while the first two animals only had about six days of training prior to surgery, these animals were trained sufficiently to complete the TPR procedure post-surgically. While their behaviors were not perfected, each day post-surgery was another opportunity to refine the training. The last animals had seventeen training days prior to surgery. We were able to collect data on all individuals post-surgery, and generally without issue.
As animals become more comfortable with the training routine, their speed and efficiency in moving through approximations will be individualized. Having those steps ready is important for success for each individual animal. In our case, animals were trained to the target behavior and a hold (stand still) behavior by their primary trainer. Once they learned these, a second trainer was introduced. It was important for the two trainers to communicate effectively, as the animal needed to be reinforced at the exact moment they executed the behavior we wanted. The animal needed to focus on the primary trainer and stand still while listening for the heartrate and while the probe was inserted, to avoid injury and discomfort. Once behaviors were established, each technician on the team was able to perform the procedure with any of the animals.
This whole process made me realize that we should introduce basic target training to our short-term housed animals whenever we can. Even if the animals do not have enough time to learn a behavior perfectly, their welfare benefits when they receive positive interactions and mental stimulation through training. Our training program has proved that with only two days of training, pigs are more likely to walk into a transport cage than those animals with zero training.
In conclusion, introducing training fosters a trusting relationship between us and our charges. We are taught that working with these animals is a privilege, and it is our duty to do whatever we can to improve their welfare, and in turn our work ethic as laboratory technicians.