Castration of male piglets (1): aspects of animal welfare and methods of anaesthesia. Although boar taint is influenced by various factors, such as diet, housing system and genetics, nearly all piglets are surgically castrated throughout the German speaking countries, where consumers seemingly have a strong dislike against boar taint. The procedure, however, is highly relevant for pig welfare, because it is carried out without prior anaesthesia, thus causing severe pain and distress to piglets. The article summarizes the legal framework regulating the castration of piglets within the European Community, in Norway, Switzerland, Germany, and Austria. The dilemma may be solved either by the application of anaesthesia while performing surgical castration or by using alternative methods, such as immunocastration, fattening of entire male pigs, development of a technique for detection of boar taint on the slaughter line, separation of sperm or genetic selection. The second part of this article provides a review on possible methods of general and local anaesthesia. Alternative methods substituting surgical castration, economic and ethical aspects of surgical castration and alternative methods will be dealt within the next issue.