In this study led by graduate student Chad Pilcher, researchers discovered that an optimum allocation of floor space per pig during transport and a longer journey time allow pigs to better handle transportation stress.

Mike Ellis, U of I professor of animal sciences, said their research started 10 years ago when it became apparent that losses of pigs during the transportation process had increased since the early 1990s. This caused great concern in the swine industry from both an animal welfare and economic perspective.

"Our goal was to understand why those losses were occurring and develop approaches to minimize them," Professor Ellis said. "Significant funding from the National Pork Board and several commercial companies, including ELANCO Animal Health and The Maschhoffs, allowed us to perform research in a controlled, commercial setting. It's a great example of how the industry came together to attack a problem and make positive change."

One of the challenges of this type of research is controlling the factors such as animal handling that contribute to losses, he said. By working with commercial producers to perform on-farm research, Ellis's team was better able to control who worked with the pigs and how they were handled while remaining in typical commercial conditions.

"We were able to perform controlled research where the pigs were handled the same so we could evaluate journey time and floor space," Professor Ellis said. "We discovered that the lower the floor space available per pig, the higher the losses can be. However, there is evidence that you can give them too much floor space. When pigs are transported, they are more likely to be thrown about if there is too much open space. If they are closer, but not too close, they can help support each other."

Journey time also affected the pig's ability to handle the stress of loading and unloading, Professor Ellis said.

"There's not much research on this topic as it pertains to transportation loss," he added. "But we have evidence that suggests short journey times could actually lead to higher incidences of losses because the pigs need a minimum amount of time to recover from the stress of loading at the farm. Normally, a pig will recover if given enough time. On short journeys, you may superimpose the stress of unloading onto animals who haven't yet recovered from the stress of loading."

Although previous recommendations from Professor Ellis and his team of researchers regarding floor allocation space have resulted in lower transportation losses (less than half of a percent of pigs in most well-managed systems), it remains a concern because the producer has invested a great amount of money to get pigs to that stage.

Co-author Bradley Wolter, chief operating officer of The Maschhoffs in Carlyle, Illinois, said working with the Ellis lab has allowed their company to lower pig losses within the supply chain between The Maschhoffs and its customers by more than one percentage unit.

"The 1 per cent reduction experienced in animal losses during transport and handling represent pigs that are carrying the full value of current market prices and creates a significant impact to the profitability of the company," Mr Wolter said. "Moreover, minimizing the loss of pigs within our production system is a moral obligation we have to society that is consistent with our core values. This important area of research continues to enhance our understanding of how we can achieve this very important commitment."

Because the industry has made such great strides to improve transportation and animal handling, this study did not show the trends and differences Ellis expected to see.

"We did visual assessments of how stressed the pigs were upon arrival at the plant," he said. "They were definitely more stressed after being unloaded from shorter journeys. But, anytime the losses are low to start with, you won't find many factors that will lower them further. As losses are reduced, it's more difficult to show how these factors are involved."

This is a good problem — and a win for everyone involved, Ellis said. Mr Wolter added that this particular study validated previous recommendations employed by their company's animal transporters.

"The results from U of I's science-based program have been incorporated in a comprehensive set of Standard Operating Procedures within our organization that are implemented by producers within the barns prior to loading the truck all the way through the process to the pig handler within lairage at our customers' operation," Mr Wolter said.

"Effects of floor space during transport and journey time on indicators of stress and transport losses of market-weight pigs" was recently published online in the Journal of Animal Science. Researchers include C.M. Pilcher, M. Ellis, A. Rojo-Gomez and S.E. Curtis of the U of I; B.F. Wolter, C.M. Peterson, B.A. Peterson and J. Brinkmann of The Maschhoffs; and M.J. Ritter of ELANCO Animal Health. Funding was provided by the National Pork Board.