Measures of behavioural reactivity and their relationships with production traits in sheep: A review

This paper defines the concept of temperament and discusses the use of behavioural reactivity testing in sheep. The range of behavioural tests used in sheep are categorised and the aspects of behaviour reflected by each type of test discussed. The activation of nervous and endocrine pathways is reviewed as the underlying physiological basis of behaviour. Factors that affect behavioural reactivity are described, and the relationships between reactivity and productivity examined. There is some evidence that behavioural reactivity has an economic impact on sheep production in regards to growth and maternal traits. As in cattle, intensive training appears not to have any significant effect on behavioural reactivity in the long term. Although few measures of heritability of behavioural reactivity have been made in sheep, those tests which have been assessed exhibit moderate heritability and thus behavioural reactivity should respond to selection. Selection on reactivity may be useful where it is related to traits that are not highly heritable or difficult to measure, and additionally to improve ease of handling and welfare of the sheep. Before behavioural reactivity can be effectively used as a selection criterion, further work must be done to investigate the nature and magnitude of these relationships. A standardised scoring system for temperament must also be established to allow comparisons across breeds and production systems.