Welfare benefits to farm animals from their use in research

Domestication is the purposeful selection and modification of livestock to suit the human-made production environments. While the application of modern breeding theory has accelerated genetic change, traditional practices also modify the genetic makeup of livestock. Threats to the welfare of farm animals can arise from husbandry practices, attributes of the production environment and failure to match the genotype to the production environment. The selection of sheep for resistance to gastrointestinal nematodes, the yard weaning of calves and the selection of cattle with docile temperament (e.g. slow flight time) are described as methods for improving welfare outcomes for grazing sheep and feedlot cattle, respectively. Contemporary production breeds exist as global populations. The move to the life-long individual identification of animals improves the power of breeding and management programmes that satisfy the criteria of scientific experimentation in their manner of implementation. In contrast to the use of farm animals, prejudice exists against comparable uses of more-recent domesticates (e.g. laboratory rodents). The growing global demand for livestock products suggests that Russell & Burch's Three Rs no longer provide a valid framework for deliberation on ethics of domestic animal use. A welfare outcome metric, such as that adopted by Grandin, is proposed as more robust than input quantification (reduce, replace) for appraisal of the ethics of animal use.