Familiarity, age, weaning and health status impact social proximity networks in dairy calves

Abstract

Social network analysis in dairy calves has not been widely studied, with previous studies limited by the short study duration, and low number of animals and replicates. In this study, we investigated social proximity interactions of 79 Holstein–Friesian calves from 5 cohorts for up to 76 days. Networks were computed using 4-day aggregated associations obtained from ultrawideband location sensor technology, at 1 Hz sampling rate. The effect of age, familiarity, health, and weaning status on the social proximity networks of dairy calves was assessed. Networks were poorly correlated (non-stable) between the different 4-day periods, in the majority of them calves associated heterogeneously, and individuals assorted based on previous familiarity for the whole duration of the study. Age significantly increased association strength, social time and eigenvector centrality and significantly decreased closeness and coefficient of variation in association (CV). Sick calves had a significantly lower strength, social time, centrality and CV, and significantly higher closeness compared to the healthy calves. During and after weaning, calves had significantly lower closeness and CV, and significantly higher association strength, social time, and eigenvector centrality. These results indicate that age, familiarity, weaning, and sickness have a significant impact on the variation of social proximity interaction of calves.

Evidence of personality-dependent plasticity in dairy calf movement behaviours derived from automated data collection

“…While this alone could have resulted in an incentive to walk longer distances daily, the move to the second housing was also concurrent with the mixing of eight pairs of calves into one pen. It is likely that mixing with new individuals could have also contributed to an increase in distance travelled as the calves might be moving around the pen to interact with each other 48 . The decrease in residence time from the pair to the group housing can similarly be explained by the change in space available to move; it is less likely that an individual will stay in the same location when there is more space available to move in, and more frequent/different social interactions may cause more frequent movement 49 .…”

Early detection of bovine respiratory disease in pre-weaned dairy calves using sensor based feeding, movement, and social behavioural data

“…The following social features: mean contact duration and number of proximity encounters, as described in Table 1 , were computed using the location data from the ultrawideband sensors worn by the calves. For the social features interactions were defined as “ proximity interactions below a threshold distance for a minimum duration of time between a pair of calves ” 44 . A 1-m spatial threshold and 3-min threshold were used for the duration as in Vázquez-Diosdado, et al 44 .…”

“…For the social features interactions were defined as “ proximity interactions below a threshold distance for a minimum duration of time between a pair of calves ” 44 . A 1-m spatial threshold and 3-min threshold were used for the duration as in Vázquez-Diosdado, et al 44 .…”

“…Full details of how movement and social interaction data were collected and pre-processed can be found in Occhiuto, et al 51 and Vázquez-Diosdado, et al 44 respectively.…”

“…Furthermore, other types of behaviours that are impacted by poor health and disease are yet to be explored. One example is that animal social behaviours that have been shown to be impacted by disease 44 , 45 and can have implications for disease transmission 46 , 47 .…”