Effect of transport stress on serum haptoglobin and pig-map in pigs

This study was undertaken in order to determine the variation of the acute phase proteins haptoglobin and Pig-MAP (major acute phase protein) in the serum of pigs affected by transport-related stress. Pigs were subjected to one of two pre-slaughter treatments: a) short-duration transport (1 h 15 min transport and 2 h lairage); or b) long-duration transport (6 h transport and 14 h lairage). There were 10 individuals in each treatment group, belonging to the NN (n = 5) or Nn (n = 5) genotypes for halothane susceptibility. Samples were taken before transport, just after transport, and on stunning at slaughter. We measured levels of serum haptoglobin, Pig-MAP and cortisol. Our results showed that the short-duration transport did not modify the levels of haptoglobin or of Pig-MAP in any of the three samples, whereas cortisol was increased just after transport. In contrast, there was an increase in haptoglobin and Pig-MAP in serum from animals after long-duration transport, as observed in the post-mortem samples (20-21 h after the beginning of transport); cortisol levels were not increased in these conditions. In this experiment, homozygotes for the halothane gene tended to have higher values of haptoglobin after slaughter than did heterozygotes. In conclusion, combined determination of acute phase proteins and cortisol levels could provide valuable information on welfare problems related to transport.