According to the current German animal welfare law, male piglets may be surgical castrated without anaesthesia up to four weeks of life. This surgical procedure is painful during and also after the operation, for newborn animals as well as for adults. This study was aimed to investigate the impact of preoperative application of analgesics (Meloxicam) on the postoperative castration - pain of four to six days old male piglets. In this investigation all animals were randomly distributed in three groups:the first one was only immobilized but had no surgery, the second one was castrated without analgesics, and the third group was castrated after application of Meloxicam. Blood samples were taken immediately before immobilization, castration or application of the analgesic as well as one, four and 28 hours afterwards to determine Cortisol-concentration in the blood serum and, via this stress-marker, to indirectly evaluate the postoperative und possible intraoperative castration-pain. As a result all piglets castrated without preoperative application of Meloxicam showed significantly increased Cortisol-concentration one and four hours after castration. In contrast, piglets castrated with analgesics resulted in no significant increase during the entire experiment.