Effects of an enriched environment of subsequent fear reactions of lambs and ewes

Qualitative categories for the interpretation of sheep welfare: a review

The aim of this paper is to discuss the relationship between qualitative categories of sheep welfare and associated quantitative behavioural observations. Most scientific studies rely on quantitative measures, however to interpret those measures in terms of an animal's experience of welfare, the use of qualitative terminologies denoting various emotional states (eg fear, pain, distress) seems hard to avoid. This is especially so in cases where the same behavioural or physiological indicator could have different meanings for welfare; high levels of locomotion, for example, could indicate fear, aggression, or both. To resolve such dilemmas, scientists often resort to judging an animal's most likely state through direct observation; indeed qualitative characterisations are often intertwined with reported quantitative results. This paper reviews frequently used qualitative categories of sheep welfare and the behavioural context in which these categories are applied. Qualitative judgements of welfare tend to habitually be regarded as ‘subjective’, ie as anthropomorphic and unreliable; however from this review it appears that such judgements reflect the overall demeanour of an animal's behaviour, and as such may provide a useful empirical basis for the investigation of emotional expression in sheep. Further development of a qualitative behavioural approach may provide a more complete picture of the expressive repertoire of sheep, and enhance our understanding of ways in which these animals experience well-being or distress.

Responses of weaned lambs to fear-eliciting situations: origin of individual differences

The aims of this study were 1) to develop methods of objectively measuring fear in weaned lambs, and 2) to evaluate the effects of age, sex, breed, and rearing conditions on fear reactions. Four hundred forty-one lambs, aged 3 to 6 months, were submitted to three fear-eliciting situations (isolation, surprise effect, and human presence). Factor analysis revealed a first factor, interpreted in terms of fear, that accounted for 40% of total variance in the three tests. As in adult sheep, the main signs of fear were inhibition of feeding, long distance from the frightening stimulus, frequent immobilizations, and numerous high-pitch bleats. Behavior was also influenced by differences in general locomotor activity and exploratory motivation. Fear reactions were influenced by age (3- to 4-month-old lambs more fearful than 5- to 6-month-old), sex (females more fearful than males), breed (Romanov more fearful than Ile-de-France), and rearing conditions (artificial vs. maternal: almost no influence in males and influence in females depending on age). These results with sheep provide interesting theoretical and practical perspectives to the study of fearfulness.