Effects of halothane sensitivity on mobility status and blood metabolites of HAL-1843-normal pigs after rigorous handling

The objective of this study was to determine if HAL-1843-normal pigs that respond abnormally to halothane anesthesia were more likely to become nonambulatory (NA) when subjected to rigorous handling than pigs that exhibit a normal response to halothane. After a 1,100-km transport, pigs exhibiting low (HS-L; n = 33), intermediate (HS-I; n = 10), and high (HS-H; n = 47) sensitivity to halothane were moved through a 36.6-m long aisle that was 2.1 m wide at each end and 0.6 m wide in the middle 18.3 m. Ten groups of 8 pigs were briskly moved down the aisle and back 4 times, receiving a minimum of 1 electrical prod per pass (8 prods/pig). Before testing, rectal temperature was measured, open-mouth breathing and skin discoloration were visually evaluated, and a blood sample was collected from each pig. After the test, the pigs were returned to their pens, and the same measurements were taken immediately posttest and 1 h posttest (no blood at 1 h posttest). Pigs that were HS-H were more prone to becoming NA compared with HS-L pigs (P < 0.02). Regardless of halothane status, a greater number of pigs exhibited open-mouth breathing and skin discolorations immediately posttest than at the pretest or 1 h posttest times (P < 0.05). No differences were observed in blood metabolites between the different halothane sensitivity categories. However, pigs that became NA had elevated blood levels of creatine phosphokinase, lactate, glycerol, nonesterified fatty acids, ammonia, and urea nitrogen before testing (P < 0.05). Collectively, these data suggest HS-H pigs are more susceptible to becoming NA than HS-L. The elevated pretest blood metabolites of NA pigs suggest that they were in a hypermetabolic state that predisposed them to becoming NA.