European Fur Breeder's Association initiated the "WelFur project" in 2009 which is aiming at developing an applicable on farm welfare assessment protocol for mink based on the Welfare Quality® principles. Such a welfare assessment system should possess the following qualities: It should be "high" in validity, reliability as well as feasibility - the latter both as regards time and economy costs. This paper based on empiric data addressed the questions on needed sample size for a robust herd assessment of animal based measures. The animal based part of the full WelFur protocol including 9 animal based measures such as "stereotypy", "tremperament" and "body condition". These measures were in each fo 9 Danish mink farms on approximately 250 adult mink on each farm collected during the nursing season 2011 by a total of 8 observers working in pairs. Descriptive result showed a large between herd variations in herd prevalence of the mentioned parameters. Statistical analyses showed that a sample size of 125 adult mink was a robus estimate of the herd level of animal based measures.
Proceedings of the Xth International Scientific Congress in Fur Animal Production, 2012, p. 420-425