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Swine & U: Cold Weather Transportation

By Jason Ertl, Ag Production Systems Extension Educator in Nicollet and Sibley countiesOriginally printed in The LAND – as December 11/December 18, 2020 Swine & U column

Fall 2020 was a prime example of the drastic temperature changes we can expect to experience in the upper midwest. On multiple occasions, parts of Minnesota went from significant accumulations of snow to above 60 degree F high temperatures in less than a week’s time. It’s seemingly harder and harder to find anything resembling “normal” in the world today, and that sentiment extends to weather patterns. With this in mind, transporters will need to take necessary steps in order to protect pigs from the elements, prevent stress and bring them safely to their destination, especially as we move into winter months and colder temperatures.

Many factors are taken into consideration when planning to move pigs from one location to another, ranging from contract obligations, available space, or farm employee/transporter schedule. Perhaps the most important factor, and one that should first be considered, is whether or not the animal is in the correct physical position to be transported. According to Effect of Transport on Meat Quality and Animal Welfare of Cattle, Pigs, Sheep, Horses, Deer and Poultry (2004) Temple Grandin concluded that one of the two main factors that contribute to the most serious animal welfare problems was the loading of unfit animals. Unfit animals, as defined by Grandin, The National Pork Board, and various other animal welfare organizations/experts, would include those that are, for example:
  • Sick, Injured or Fatigued
  • Temporarily unable to stand or bear weight on each leg
  • Those that cannot be moved without causing additional suffering
  • Pregnant animals during the final 10% of the gestational period at the planned time of unloading
  • Females traveling without young who have farrowed within the past 48 hours
  • Newborns with unhealed navels
  • Those whose body condition would result in poor welfare because of the expected climatic conditions

Depending on the symptoms and severity, some pigs will have the ability to recover and would be able to be loaded onto trucks at a later time. Additional influences, such as poor handling practices, or those in combination like the presence of the stress gene and high doses of ractopamine, can exacerbate underlying conditions and influence an animal’s fitness to travel. In a situation where pigs are non-ambulatory and show a low probability of recovery, even with treatment, transportation is not recommended and they should be humanely euthanized on the farm. 

How many pigs to load?
The Transport Quality Assurance (TQA) Handbook has a table (p 29) with helpful information about space recommendations for pigs, providing an idea of space requirements in square feet based on average weight of the animal.

While helpful, this table does not take into account temperature considerations, requiring transporters to adjust these numbers with respect to current weather conditions. It may be reasonable to assume that during colder temperatures, adding more pigs onto a truck or trailer would generate more body heat and lead to a more comfortable mircoenvironment. This concept, however, is incorrect. While there may be more body heat generated, movement within the trailer space would be limited and those pigs against the sidewalls of the trailer are more likely to experience colder temperatures and a higher likelihood of frostbite. While being kind of nuanced, there are other ways to recognize when a loading density is too high-- including responses like abnormally high amounts of vocalization or squealing, fidgeting, or fighting within compartments. Travel time must also be taken into account; it is recommended to provide additional space per pig for trips lasting longer than 3 hours, regardless of temperature. Using resources like the TQA Handbook (v. 7), having an understanding of pig behavior, and previous experience with the hauling equipment used will enable transporters to achieve optimal load densities given weather conditions.

Movement of pigs between the different production phases can sometimes include traveling significant distances and across different weather conditions, making it essential for transporters to know the current and future forecast. Today’s technology allows us to have these live and local updates at our fingertips through smartphone apps, but at a minimum, dialing in to local radio stations or local news will provide at least an idea of what to expect throughout the route.

During the winter months, the combination of cold temperatures and wind speed create windchill, a table in the TQA Handbook (p 31) shows the relationship of wind and temperature on pigs and provides the period of time, in minutes, for frostbite to occur if pigs are left unprotected.

Pigs are similar to humans in a number of different ways, including our sensitivity to cold temperatures. We both lack the warm, insulative coat that protects many other livestock species from the elements. Transporters, then, have the responsibility to provide an environment that will protect pigs from those conditions, and can do so in a few different ways.

One of the major ways to reduce cold stress or the potential for frostbite would be by closing trailer vents & gaps with boarding or paneling. Even on the calmest of days, traveling down the road at speed will create a chilling effect within an unprotected trailer. Again the TQA Handbook (p 33) has a table with truck set-up procedures including recommendations for side-slat coverage over different temperature conditions. It is important to note that these recommendations never exceed 95% closure. Even on the coldest of days, some air exchange is necessary to improve air quality within the trailer, decrease humidity, and decrease the potential for suffocation .

Information about bedding can also be found within the TQA Handbook. In the previously mentioned wind chill table, recommendations for appropriate amounts of bedding during specific outdoor temperatures will achieve the primary goal of keeping animals dry, in addition to absorbing moisture and providing footing to reduce the amount of slips or injury.

While 50 lb bales are used as standard measure for bedding, the addition of straw will provide an added layer of insulation during the trips. Chutes and other load-out alleys are often overlooked areas in the transportation process; producers and transporters should work cooperatively to make sure these locations are bedded in a manner that provides proper footing to animals as they enter and exit the trailer.

Hauling and transporting pigs is a process that involves many new experiences to pigs. They face physical requirements which include moving up and down alleys, chutes and through doorway thresholds. They can be mixed with other animals without a previously established hierarchy, and can be subject to handling techniques or equipment different from that to which they are accustomed.

On top of that, like humans, pigs can experience motion sickness, with some being more tolerant to transport that others. When combined with processes associated with transportation stress, the environmental stressors, such as exposure to cold temperatures, can increase their levels of discomfort and have effects on meat quality.

In a US National Pork Benchmarking Study (Scanga et al., 2003) packers indicated that weather was the largest influence upon carcasses or wholesale cuts exhibiting undesirable Pale, Soft Exudative (PSE) pork. This research serves as a reminder that while efficiency or convenience may be important in transportation practices, producers and transporters need to consider the effects these stressors will have on the pigs, and in how those results will be passed on to the consumer. By following some of the concepts described above, in addition to those detailed in the current PQA+/TQA handbooks, we can ensure the safety and quality of the pork entering the food chain, and provide consumers with the pleasurable eating experiences that keep them returning to the pork section of the meat case.

The National Pork Board has been at the forefront of the livestock industry when it comes to establishing producer and consumer standards. Programs like Pork Quality Assurance Plus (PQA+) and Transport Quality Assurance (TQA), provide caretakers, handlers and haulers with the resources to build a stronger industry and define the best practices for production, management and transportation of swine in the US; all of which impact pig well-being and pork quality for the consumer. For more information about the PQA+ and TQA Programs, or to locate a local quality assurance certification advisor, visit

Refer to updated TQA manual for further information about cold weather transportation

Jason Ertl is an Extension Educator of Agricultural Production Systems for the University of Minnesota Extension. His email is
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