Social bonds in dairy cattle: the effect of dynamic group systems on welfare and productivity

The recent increase in intensification of the UK dairy industry has led to the majority of cattle in the UK being housed in large, dynamic groups. Proposals for two large-scale dairies intending to house between 3,000 and 8,000 head of cattle have been met with considerable opposition by both producers and the public alike. Recent reports by both the Farm Animal Welfare Council and European Food Safety Authority have highlighted the continued welfare issues relating to dairy cattle, especially those housed in such large, dynamic groups. Conversely, with the current economic challenges being imposed on the UK dairy industry, there are many who see these systems as the future of dairying and discount the welfare concerns being highlighted. This project aimed to address one of the main welfare issues that receives scarce consideration when designing such systems; the social bonds of dairy cattle. A herd of 400 Holstein-Friesian cattle, plus followers, were observed in cubicle housing under commercial conditions. Through the identification of preferential relationships using an association index, important social bonds between individuals were identified. The majority of relationships between dyads were however weak, short term associations appearing together no more than once throughout the observation period. These bonds were significantly stronger in younger cattle demonstrated through the closer proximity maintained and the higher association index scores between dyads. Between the ages of 7 & 11 months animals performed the most positive social behaviour and had the strongest dyad relationships. In order to assess the strength of these positive relationships between dyads and to investigate the importance of these relationships to cattle, a short term (30 minutes) separation test from the remainder of the herd was carried out. Cattle’s responses to the challenge were assessed both physiologically and behaviourally. A significantly lower heart rate (p