This paper derives from a 2007 European Science Foundation Workshop on genetic models of disease resistance in livestock. Research in this area, enabled by ‘expanding knowledge of the genomics of key livestock diseases, together with the latest techniques on genetic modification,’ the organisers stated, is likely to have a ‘major impact on animal welfare, food safety, the economy of the sector and human health.’ What ethical issues are raised by this? The author was invited to discuss them by addressing the question: “What does our conscience want?”