ATTEMPT TO ASSESS TRAITS OF EMOTIONALITY IN CROSSBRED EWES

Behavior of sheep isolated in a 6 m diameter enclosure, then exposed to a tethered dog in the same setting, was examined. Subjects were 2 and 3 year old crossbred ewes (North Country Cheviot, Dorset, Finnsheep, and Romney sire × Suffolk and Columbia-type dam matings). Each of 164 ewes was tested three times with 3 weeks between tests. Ewes were scored for ambulation (number of steps taken) when isolated for a 90 s period and when exposed to the dog for an additional 90 s period. Subjective investigation score, subjective emotional behavior score, number of vocalizations, number of foot-stampings, and number of eliminations (urinations plus defecations) were also examined. These traits were chosen because published research with farm mammals and rodents has indicated they are related to emotional behavior or nervousness. Ewes typically responded to isolation by initial high levels of ambulation which decreased to immobility by the end of the first 90 s. Vocalization occurred in 73% of the observations but foot-stamping occurred very rarely in the first 90 s of observations. Upon exposure of the dog, ewes commonly took several steps, then became and remained immobile for the duration of that 90 s observation. Vocalization was rarer but foot-stamping was much more common than during the period in which ewes were isolated. Eliminative behavior occurred in 53% of the observation periods and was not affected by exposure to the dog. In this experiment, high ambulation during isolation was related to greater emotional behavior, while immobility during exposure of the dog was related to greater nervousness. Vocalization and foot-stamping were predictable responses to isolation and dog exposure, respectively, but both occurred with too low a frequency to be useful measures of variation in emotional behavior. Differences between ewes with Suffolk vs. Columbia-type inheritance were small and not consistent. Ewes with Romney sires had higher scores for ambulation, investigation score, emotion score and vocalization, and ewes with Finnsheep sires scored above average for vocalization and eliminative behavior. Dorset and North Country Cheviot sired ewes were average or below for most of the traits assessing emotional behavior. © 1979.