MSU research aims to curtail pig fighting on swine farms

MSU AgBioResearch scientist Janice Siegford is leading a multidisciplinary effort to find ways to curb fighting, and enhance swine productivity and quality of life with a nearly $750,000 grant from the U.S. Department of Agriculture.

Piglets. Photo courtesy of MSU Communications and Brand Strategy

EAST LANSING, Mich. – Fighting, a common behavior seen in groups of pigs, poses serious risks such as injury, infection, stunted growth and failed pregnancies on pork farms. A Michigan State University (MSU) AgBioResearch scientist is leading a multidisciplinary effort to find ways to curb fighting and enhance swine productivity and quality of life with a nearly $750,000 grant from the U.S. Department of Agriculture (USDA).

Janice Siegford, an assistant professor of animal science, said pigs raised in agriculture are grouped together by age, weight and sex, which often leads to conflict when pigs try to establish social hierarchies. In wild pigs, which live in small, matrilineal family groups, fighting typically occurs only to settle disputes between rival dominant animals in the group.

“What we’re essentially trying to do is figure out whether these aggressive social behaviors in pigs on farms are heritable and if we can select genes through breeding that show improved behavior and less fighting,” she said.

Pigs are most likely to fight when first put into groups, but the study will examine if the aggressive behavior changes over time. The research team will observe eight groups of 140 pigs each from birth to the time they would either be sent to market or separated for breeding. 

“During the first 72 hours after meeting, the pigs can literally beat the snot out of one another,” Siegford said. “There’s a lot of biting and smacking heads together, and the bigger the pig, the harder it bites and the more serious the injuries.”

The researchers will collect 24 hours of video when the pigs are introduced and another 24 hours three weeks later. The team will analyze the behavior that each pig displays and count the incidence of injuries. They will also compare the behaviors of each pig with genetic samples to determine whether heredity plays a role in aggressive tendencies. The results will be compared to similar data collected by colleagues in Scotland, which suggested that a pig’s aggressiveness could be determined in part by where its injuries appeared on its body. A pig with wounds near its head was said to be more aggressive because it was likely to either instigate or reciprocate combative behavior. Those with injuries around the tail end were suggested to be more passive because their injuries were sustained while fleeing aggressive encounters.

“We’ll have three sets of behavioral data for each pig, which will let us track not only the patterns of aggression in the herd but also the signals that pigs use to signify submission or group cohesion,” Siegford said. “Cattle, for example, like to groom one another as a sign of cohesion. Pigs don’t do that, but this study can help us look for other signs that tell us that a particular group is good together and the personalities in it are complementary.”

As concern over the health and care of animals mounts, the World Trade Organization and animal health organizations are developing animal welfare standards for farms. Siegford said her ultimate goal is to give pork producers in the United States the tools they need to meet these new standards while remaining economically viable. She plans to host workshops with farmers to discuss the results.

“We want to make sure our producers can meet the new standards so they can continue to compete in the global market, as well as ensuring that we have a stable and secure food system here at home,” Siegford said. “When the United Kingdom made the transition to new welfare standards, it lost about 30 percent of its pork producers because of how difficult it was to adapt. We want to make sure our producers have the right tools so that doesn’t happen here.”

In addition to the USDA three-year grant, Siegford’s work is supported by funding from the MSU Rackham Foundation and the National Pork Board.

MSU AgBioResearch engages in innovative, leading-edge research that combines scientific expertise with practical experience to generate economic prosperity, sustain natural resources and enhance the quality of life in Michigan, the nation and the world. It encompasses the work of more than 300 scientists in seven MSU colleges -- Agriculture and Natural Resources, Arts and Letters, Communication Arts and Sciences, Engineering, Natural Science, Social Science and Veterinary Medicine -- and has a network of 13 research centers across the state.

Did you find this article useful?