Dairy goats use outdoor runs of high quality more regardless of the quality of indoor housing

For dairy goats in loose housing, access to an outdoor run has potential welfare benefits as it provides additional space, enables spatial separation and may offer items representing behavioural enrichment for the goats (e.g. brush, climbing possibilities). However, these benefits will only apply if the outdoor run is actually used, and the use may depend on the attractiveness of the outdoor run and the (un)attractiveness of the indoor housing. The aim of the study was therefore to examine the use of the outdoor run and the activity behaviour of goats in loose housing systems in closed buildings in relation to the quality of both the outdoor run and the indoor housing. On 13 farms, this quality was assessed with an outdoor and an indoor index. A high index indicated high quality in terms of the number of resources provided (outdoor index: e.g. space allowance, accessibility of the outdoor run, wind shelter, brushes, hayracks; indoor index: e.g. space allowance, lying niches, separate feeding place, brush). During the winter feeding period, 3-7 days per farm with comparable weather conditions were selected for analysis. The average daily time-weighted proportion of the herd in the outdoor run was assessed by video data. The activity behaviour of 15 focal goats per farm was measured using 3D acceleration loggers. The age of the focal goats was used as a proxy for social rank. Linear mixed-effects models with a stepwise backward selection approach were used for statistical analysis. Direct observations showed that the goats used all enrichment items provided in the outdoor run, and most of the individuals were seen in the outdoor run at least once. With increasing outdoor index the average daily time-weighted proportion of the herd in the outdoor run increased (p = 0.023). Additionally, an increasing outdoor index was associated with a decreasing total daily activity in lower ranking goats and an increasing total daily activity in higher ranking goats (p = 0.028). The indoor index had no influence on the average daily time-weighted proportion of the herd in the outdoor run, but the number of lying bouts per day decreased with increasing indoor index (p < 0.02) and with increasing rank status (p < 0.001). We conclude that an outdoor run influences the activity of goats and its use can be promoted by increasing the number and types of resources provided there, regardless of the quality of the indoor housing. Furthermore, indoor housing systems of high quality are beneficial for lying behaviour, as seen in the reduced number of lying bouts.