Validation of welfare assessment methods at herd level: An example

Validity is a measure of the extent to which a method measures what it is s upposed to measure. It is therefore a relative concept in the sense that it is defined in relation to the aim of the method. The comparison of methods with similar aims can provide information on validity. In order to make su ch a comparison, welfare was evaluated in 10 Danish dairy herds using two d ifferent welfare assessment methods: an environment-based method (TGI200) a nd an animal-based method (factor analysis of individual animal observation s). The results of the assessments were compared, and their agreement and d isagreement were investigated and discussed. A fairly non-significant corre lation (r = 0.31, p = 0.38, n = 10) was observed between the two methods.