Differences in the Spacing Behaviour of Two Breeds of Domestic Sheep (Ovis aries) - Influence of Artificial Selection?

The aim of this experiment was to investigate differences in spacing behaviour, measured by the individual distance when resting and feeding, between two breeds of sheep with a different selection history. Eight groups of four pregnant ewes from the Nor-X breed (a heavy, composite breed mainly selected for growth and meat quality) and eight groups of four pregnant ewes of the coloured Spael breed (a light breed, mainly selected for wool quality) were placed in oblong experimental pens for 7 d. The distance between animals was measured from digital video recordings. The heavy Nor-X ewes kept a significantly larger individual distance to their pen mates both during resting and feeding compared with the lighter Spael ewes. Spael ewes also kept a significantly smaller individual distance during resting than during feeding, but this difference was not found in Nor-X ewes. Our results indicate that selection for growth and meat quality might influence spacing behaviour in sheep. Looking at the selection history of these two breeds, we discovered differences in how long they had coexisted with large carnivores. The possible effects of previous exposure to carnivores and the role of domestication in modifying spacing behaviour are also discussed.