A capacity for the animal to recover quickly from the impact of physical and social stressors and disease challenges is likely to improve evolutionary fitness of wild species and welfare and performance of farm animals. Salience and valence of stimuli sensed through neurosensors, chemosensors and immunosensors are perceived and integrated centrally to generate emotions and engage physiological, behavioural, immune, cognitive and morphological responses that defend against noxious challenges. These responses can be refined through experience to provide anticipatory and learned reactions at lower cost than innate less-specific reactions. Influences of behaviour type, coping style, and affective state and the relationships between immune responsiveness, disease resistance and resilience are reviewed. We define resilience as the capacity of animals to cope with short-term perturbations in their environment and return rapidly to their pre-challenge status. It is manifested in response to episodic, sporadic or situation-specific attributes of the environment and can be optimised via facultative learning by the individual. It is a comparative measure of differences between individuals in the outcomes that follow exposure to potentially adverse situations. In contrast, robustness is the capacity to maintain productivity in a wide range of environments without compromising reproduction, health and wellbeing. Robustness is manifested in response to persistent or cyclical attributes of the environment and is effected via activity of innate regulatory pathways. We suggest that for farm animals, husbandry practices that incorporate physical and social stressors and interactions with humans such as weaning, change of housing, and introduction to the milking parlour can be used to characterise resilience phenotypes. In these settings, resilience is likely to be more readily identified through the rate of return of variables to pre-challenge or normal status rather than through measuring the activity of diverse stress response and adaptation mechanisms. Our strategy for phenotyping resilience of sheep and cattle during weaning is described. Opportunities are examined to increase resilience through genetic selection and through improved management practices that provide emotional and cognitive enrichment and stress inoculation.

Behavioural, endocrine and immunological measures made at weaning or feedlot entry were examined for associations amongst them and with feedlot performance with a view to identifying predictors of the suitability of cattle for feedlot finishing. The 24 animals used in this experiment were chosen to represent the extremes of temperament amongst 209 beef steer calves that were weaned at 7–9 months of age. From a subgroup of 50 animals that were paddock-weaned without handling or supplementary feeding, the 12 animals with the worst temperament were selected on the basis of flight time and crush behaviour assessment. From a matched subgroup of 100 animals that were weaned in yards and hand fed for 10 days, the 12 animals with the best temperament were selected on the basis of flight time, crush score and a novel behavioural test performed as follows. Each morning, fresh hay and a small amount of grain were offered in an adjacent pen and calves were scored on their willingness to walk past an observer standing by the gateway between the 2 pens. These 2 experimental groups were designated as ‘nervous’ and ‘calm’, respectively. Blood samples were collected at the start and end of weaning for cortisol assay. On entry to a commercial feedlot 6 months later, blood samples were collected for cortisol and immunological assays on day 1 (immediately after induction processing) and day 5 (after 4 days in the feedlot pen). The nervous group had significantly higher cortisol levels at weaning and at the feedlot and, after 85 days on feed, had significantly lower average daily gain and significantly higher morbidity than the calm group. Groups did not differ in total and differential leucocyte counts, lymphocyte proliferation, production of the cytokine interferon, natural killer cell activity, neutrophil myeloperoxidase activity, lymphocyte subsets (CD4, CD8 or WC1), and serum concentrations of IgA, but IgM was lower in the calm group. Significant correlations were found between cortisol and a number of haematological variables, flight time, and average daily gain. The correlations suggest that desirable traits at feedlot entry may include slow flight time, low crush score and high confidence score, low cortisol, low total white cell count, low neutrophil count, high CD8 + lymphocyte percentage, high lymphocyte proliferative activity and high IgA concentration. Relationships between behavioural traits and immunological measures may have utility in predicting the suitability of individuals for the feedlot environment.