Supporting Feeding Management of Individual Grazing Cattle with Intra-group Relationships Analysis Using Location Data

Practices of beef cattle grazing on abandoned farmland are increasing in Japan to address food security issues. One of the challenges lies in the application of supplement feed as an important mechanism for maintaining the balance of forage supply and demand throughout the year because both the productivity of the land and the cattle could be damaged by improper feed supply. Acquiring supportive information for decision-making regarding cattle growth traditionally relies on on-site measurements of the cattle's body weight. However, conducting frequent weight measurements poses significant challenges. To address this issue and detect potential problems in energy acquisition at an earlier stage, observing the stability of intra-group relationships exhibited in foraging behavior can be effective. Because the balance between individual choices to follow the group or act independently to satisfy personal needs can be disrupted due to the changes in resources. In this study, we propose a method of using location data of cattle to extract the leader-follower relationships between individuals and the group as an indicator and verify its effectiveness in inferring the energy status of individuals. The location data were collected from five grazing cattle for 56 hours in October and November 2022 in Kagoshima. By analyzing the individual-group relationships and comparing them with the body weight data of cattle, we found that changes toward a stronger tendency to follow the group, characterized by higher influence received from the group on individual movement decisions and less contribution to the group's collective movement decisions, could be indicative of inadequate energy intake. This finding reveals the potential of monitoring individual-group relationships to detect the unbalanced conditions of food access among individuals and provides insights into the dominance structure of the group. Verifications in the longer term and in diversified settings are needed to clarify its scope of applicability.