Evidence shows that …show more content…
Pain is subjective and cannot be assessed directly and must be measured by indirect means. In this set of experiment, five day old piglets were either castrated or restrained in the same way but not castrated. Two experiments were conducted to assess piglet behavior after castration. In both experiments, the same person for all piglets to ensure consistent methods administered the castration. The castration or restraint method also did not change. In the first experiment, scan sampling was conducted every three minutes starting at 14:00 h on the day of castration and lasted for only three hours. Blood samples were taken from piglets before castration then every hour after for 4 hours total. In the second experiment, scan sampling was conducted on the day of castration and three days directly after. On day one, scan sampling was done in the morning, between 10:30-130h, and afternoon, between 14:00-16:00. On days two through four, scan sampling was only conducted in the afternoon between 14:00-16:00. Blood samples were taken before castration and at 12, 24, 48, and 72 hours after. In both experiments, behavior was observed and recorded by the same-trained person. The blood samples were analyzed for pro-inflammatory cytokines TNF-α and IL-1β by ELISA. No differences were found between experiments. In experiment one, castrated piglets had less movement behavior and stayed closer to the