Environment and Behavior - Animal Sciences Colorado State University Updated December 1999 Handling Pigs for Optimum Performance on the Farm and in the Slaughter Plant Temple Grandin, Colorado State University, Fort Collins, Colorado Observations at packing plants indicate that some lines of hybrid pigs have a very nervous temperament and others are calm.
Some pigs are easy to drive up chutes and others are nervous and constantly balk and back up.
Certain lines of lean pigs, which contain the stress gene, tend to be more nervous and excitable than lean lines without the stress gene. Observations at large packing plants have also indicated that lines with some Duroc genetics tend to be calmer. Lines with Hampshire or Pictrain genetics tend to be more nervous. She also found that they balked more during driving. Some producers have moved away from lines which are extremely nervous and carry the stress gene.