Individual Variation in Response to Stressors in Farm Animals: Implications for Experimenters
Physiological and behavioural responses to stressors may affect experimental results. Since individual animals differ in their pattern of response to stressors, it is suggested that stress during experiments has the potential for increasing variability in responses to experimental treatments.
Evidence supporting this is given from experiments carried out on farm animals. The main factors accounting for individual differences in response to stressors such as handling are habituation, early experiences and genetic background. Several ways of reducing stress during experiments are
suggested and the need for skilful and humane handling is emphasized. It is concluded that reducing stress during experiments will have welfare benefits and may reduce the number of animals that need to be used.