One ISU graduate student has been researching the social behavior of piglets to determine the best method for caring for the animals. Shawna Weimer, graduate student in animal science, conducted an experiment that studied how the behavior of pigs varied with different approaches.

This study involved piglets and two methods of observation: live observation and digital imaging.

Weimer helped with this experiment, which tested if the method of digital observation was more effective in assessing the behavior of piglets, particularly in their willingness to approach a human.

“What initiated this research is that people were noticing that after six hours, pigs would become more lethargic after some vaccines. It was first an observation, but now it’s actually being measured,” Weimer said.

She presented her study “Willingness to approach: Live human observation and digital image” at the American Dairy Science Association-American Society of Animal Science Midwest meeting in Des Moines in March.

A vaccine company hired Weimer to run the experiments at a commercial pig nursery in western Iowa.

“I was brought in to test that the digital image should be taken at time of the measurements to solidify its use,” Weimer said.

For the tests, Weimer would enter the pig pens and set up the camera behind her at the gate.

“I would look down for 15 seconds with my hand stretched out, and then I would look up and take the picture at the same time,” she said.

Weimer, while crouching in the pen, would record the number of pigs making physical contact with her, making eye contact with her or not doing either.

She further recorded whether the pigs making physical or eye contact with her were sitting, standing, laying down, eating, drinking water or “pilling,” which is considered a fearful behavior.

Weimer then analyzed the images she took and looked for the same behaviors.

“I was comparing the numbers recorded between live observation of pig behavior and the digital observation of the pigs,” Weimer said.

Weimer said in a live observation, she would sit there making observations and would only have about 30 seconds to do it, whereas with the digital image, the observations were recorded forever.

The results of the study concluded that either method could be used.

“The more practical method is the live observation, because it’s quickest and doesn’t require a lot of analyzing pictures. The digital image method, though, is more accurate,” Weimer said.

Wildlife animal behavior has been studied for quite a while now.

“Studying animal behavior has been around in wildlife since Darwin, but food animal behavior wasn’t really taken into account until Ruth Harrison wrote her book ‘Animal Machines’ in 1964,” said Monique Pairis, graduate student in animal science.

In “Animal Machines,” Harrison exposed factory farming for the first time to the public and inspired Britain’s first farm animal welfare legislation, the 1968 Agriculture Act.

“She was the first to ask what kind of environment food animals were in and how it was affecting them,” Pairis said.

Now the behavior of production animals is studied in many different ways.

“Food animal behavior can be looked at in three ways: from production aspect, emotional state and natural behavior,” Pairis said. 

Pairis, who is currently studying how sickness and lameness affects sows, said that video has become the major way of studying production animal behavior.

“It’s a good way to compare a sick animal’s behavior to that of a healthy one,” Pairis explained.

There are other ways of studying pig behavior as well.

“We also use preference testing. For example, if we lay out sawdust and straw and let a pig into the room, which one will they choose that they like better,” Pairis said.

Pairis has also done a study on pig fearfulness, somewhat similar to the study Weimer did.

“I did a test where I would be in a novel room in bright orange, and they would introduce a pig into the room and see how willing it was to touch me. We then reintroduced them into the room with another pig, and we found that if they were introduced with a partner, they were much more willing to come up and touch me,” Pairis said.

This showed that pigs are social animals and like to be in a herd environment.

Findings like these are important for researchers, producers and farmers.

“This is important for people like farmers because they shouldn’t move pigs by themselves because they are social animals,” Pairis said.

“We are trying to present it as producer friendly and as simple and quick as possible, not just a research paper,” Weimer said.

Both Pairis and Weimer agreed on the importance of studying pig behavior.

“Studying pig behavior is important because it is an indicator of welfare, whether it be good or bad,” Weimer said.

Pairis said that the major importance was to combine the three aspects of studying food animal behavior to get the best results.

There are still many things about studying pig behavior that need to be figured out.

“We need to develop methods to measure the behavior,” Weimer said.

There are also a few different aspects of pig behavior that Pairis believes should be studied.

“I think there needs to be more studying in sickness behavior in pigs and whether or not a pig would do better in isolation or in group setting, because they’re so social,” Pairis said.

There are also things to work out with the study.

Weimer said that there was still work that needed to be done with the study to make sure it’s “objective, reliable and repeatable.”