Michigan Alliance for Animal Agriculture

In 2009, the Michigan Legislature passed an amendment to the Animal Industry Act introducing a series of new standards for gestating sows, laying hens and veal calves. Juan Steibel and Janice Siegford, associate professors, and Cathy Ernst, professor, all within the Animal Science Department at Michigan State University (MSU), are working to understand the most efficient and safe methods for meeting these new requirements for swine and poultry.

By April 1, 2020, all producers will need to house pregnant pigs in stalls where they can turn about freely, something typically not found in most current operations.

The majority of agricultural producers don’t have the physical capacity to give each sow an individual pen. And though pigs are social by nature, they don’t always get along well in group settings. Researchers at MSU and Scotland’s Rural College are looking for ways to place pigs so they are more likely to live in harmony together. The basis for the solution may be rooted in genetics.

“There is great potential for selecting animals that are better adapted to group housing, maximizing group performance and reducing aggression,” Steibel said. “But we have observed that better phenotype collection and modeling will be necessary to implement desirable selection objectives in the pig breeding industry.”

Pigs naturally live in small groups that consist of their mothers and other close relatives. There is a social hierarchy within these groups, which normally works to reduce aggression and fights because they know the social order. When unrelated pigs are mixed in a shared space, fighting can become intense.

Breeding programs have traditionally focused on production traits and other relatively easy-to-measure physical characteristics, such as number of offspring, growth rate and depth of back fat. Though it’s sometimes difficult to quantify, Siegford said that behavior should also be taken into consideration.

Steibel, Siegford and the rest of the team are characterizing social interactions, relating those behaviors to health and productivity, and identifying the genetic components that factor into certain behaviors.

Researchers hope that the work will help to answer a critical question: Can pigs be selected for heritable behavioral traits that lessen the severity of conflict among grouped animals?

MSU researchers are compiling behavioral and genomic data from more than 1,000 pigs at the MSU Swine Teaching and Research Center. The data will be combined with information from 3,000 pigs obtained by collaborators Simon Turner and Rick D’Eath of Scotland’s Rural College, experts in analyzing aggression heritability in pigs.

Most previous research on heritability of aggressive behavior has been dedicated to the finishing stage of production when animals are being prepared for market. Siegford believes that monitoring interactions earlier could be useful.

With support from the Michigan Alliance for Animal Agriculture, Siegford and her students also study enclosures that allow hens more space to roost, eat and move, and the impacts on health, safety and well-being.

In the past, chicken enclosures were designed to optimize farm economics, food safety and chicken population management. This meant keeping chickens in small enclosures that protected them from some of their more dangerous behaviors such as panic attacks or establishing a literal, violent pecking order. It inhibited their ability to engage, however, in other beneficial behaviors. In exploring new enclosure types, Siegford hopes to balance the needs of the farm and the safety of the chickens with the chickens’ own behavioral health.

“Our needs and theirs aren’t in perfect synchronicity,” Siegford said. “If we can develop a system that allows chickens to engage in more chicken-like behaviors, like dust baths and freely perching and nesting, we can reduce stress on each in­dividual and, therefore, boost the overall production of the farm.”