Resting pattern and social interactions in goats—The impact of size and organisation of lying space

Abstract

The aim of the present experiment was to examine how size and organisation of lying space affected resting pattern and social interactions in female goats. Twenty-four goats of a Norwegian milking breed divided into six groups, were systematically rotated between six experimental pens (width×depth: 2.0m×3.0m) with resting areas of different size (small: 0.5m2, medium: 0.75m2 or large: 1.0m2) and organisation (one versus two levels/heights). Resting pattern was analysed using instantaneous sampling with 10min intervals for 24h, whereas social interactions were continuously observed in 5h between 09.00 and 14.00 during the last 24h of each experimental week. Individuals within each group were ranked from 1 to 4 (1 being the dominant individual) according to how many times they had withdrawn from an interactions and avoided contact with another goat throughout the entire experimental period. By using MatMan (Software for matrix manipulation and analysis), we converted a matrix of withdrawal and avoidance interactions among the goats (based on all treatments) in each group into a matrix of dominance relationships.The goats spent less time resting (P<0.01) and rested less simultaneously (P<0.001) when the resting area was small compared to a medium and large resting area. Time spent resting in the activity area also increased with decreasing lying space (P<0.01). The goats preferred resting close to a pen wall, and this occurred more seldom when the resting area was small (P<0.01). Resting in social contact with pen-mates occurred in less than 6% of the observations lying, and this was not significantly affected by the size of the resting area. When the lying space was organized on two levels, one or two goats resting at the same time on the same level was most commonly observed. In most pens, the lowest ranked individuals in the groups spent less time resting (P<0.01), less time resting against a wall (P<0.01), and spent more of their resting time in the low-comfort activity area (P<0.0001). The amount of social interactions was not significantly affected by the size of the resting area, but there were significantly fewer displacements (P<0.01) and the overall aggression level was lower (P<0.05) when lying space was organised on two levels rather than one. In conclusion, time spent resting and resting pattern was more dependent on size (large, medium, small) than organisation (one versus two levels) of the lying space, whereas this was the opposite for social interactions.