Maintain performance through summer heat – Part 3

By Dr. Leah Gesing

Although pig losses during any phase of production are costly, pig losses near the time of marketing are the most expensive.

It has been estimated that approximately 1 percent of pigs in the U.S. are classified as “transport losses.”  Transport losses refer to pigs that die or become non-ambulatory (injured or fatigued) at any stage of the marketing process.  Pigs become fatigued due to stress and the marketing processes often subject pigs to multiple stressors over a short time period.

Pigs die during transport at the highest rates during the summer, and the highest overall incidence of transport losses occurs in the approaching fall months (Rademacher and Davies, 2005).  Therefore, summer is a good time to involve all people who participate in the marketing process in a review of practices that may reduce transport losses.

Pre-sorting
Pre-sorting pigs prior to marketing has been shown to reduce the incidence of transport losses.  In a study completed by Johnson et al. (2010), researchers found that pigs that were pre-sorted 24 hours prior to loading had 66 percent fewer transport losses than pigs that were not pre-sorted prior to loading (0.30 versus 0.89 percent; or about six fewer pigs of every 1,000 marketed).  Having pigs pre-sorted ahead of time also makes loading go faster.  This reduces the amount of time loaded pigs are waiting in a stationary trailer where the ambient temperature and relative humidity are both rising.

Small groups
Moving pigs in small groups has been shown to be advantageous to moving them in larger groups.  Berry et al. (2009) conducted a study comparing the moving of groups of four versus eight pigs.  Pigs moved in groups of four had a 56-percent decrease in transport losses compared to pigs moved in groups of eight (0.55 versus  1.26 percent or about seven fewer pigs out of 1,000).  Pigs moved in smaller groups are also less likely to become wedged in the alleyway on the way to the trailer.  Anderson et al. (2002) found that pigs that became wedged in the alleyway when being moved were more susceptible to becoming non-ambulatory.

Handling tool
The type of handling tool has been shown to greatly impact the incidence of transport losses.  For example, Correa et al. (2008) reported that pigs moved from the home pen to the trailer with an electric prod and a sorting board had a 3-percent incidence of transport losses compared with 0-percent incidence in pigs moved with a paddle and sorting board (a difference of about 30 fewer pigs out of 1,000).

Additionally, a study by Benjamin et al. (2001) reported that pigs moved with the frequent use of an electric prod had a 10-percent incidence of transport losses overall, whereas pigs that were moved with a plastic cane had 0 overall transport losses (a difference of about 100 pigs out of 1,000).  These studies demonstrate that the use of an electric prod during marketing greatly increases transport losses and should be absolutely minimized.

Trailer conditions
Finally, trailer conditions also have a significant impact on pig transport losses.  Ritter et al. (2007) reported that transport losses were minimized at a stocking density of approximately 5 square feet per pig and greater.  It’s important to also remember, however, that the number of pigs loaded per truck may need to be adjusted depending on the average weight of pigs.

A number of events at marketing have the potential to lose or decrease the full value of a market weight pig.  The Vita Plus swine nutrition team is available to help you identify factors that may affect transport losses for your farm and help you to recapture the full value of your pigs.

References available upon request.

Editor’s note:  This article is the third of three articles related to wean-to-finish summer performance and management challenges.  Follow the links for Part 1 and Part 2.

About the author:  Dr. Leah Gesing is a Vita Plus swine technical sales and support specialist.  She earned her bachelor’s degree in animal science from Iowa State University.  She continued there to earn her master’s degree in animal physiology, studying on-farm factors affecting market hog transport losses.  She then went on to the University of Illinois to earn her Ph.D. in animal sciences.  While in school, Gesing was involved with numerous research projects, teaching experiences, internships, and international travel.  Specifically, she conducted applied research in swine genetics, health, management and reproduction with Dr. Mike Ellis.  Her Ph.D. project evaluated the effect of timing of OvuGel® administration on reproductive performance in gilts synchronized for estrus.