Precision monitoring of dry dairy cows herd: effects of environmental conditions, grazing availability and social network behavior

Access to outdoor space for dry cows is strongly influenced by environmental conditions, feed availability, and social dynamics within the barn. Understanding the interplay among these factors can support precision herd management strategies aimed at enhancing cow welfare and health. This study aimed to assess how environmental conditions, grazing forage availability and social dynamics influence the behavior of a dairy cow herd, based on their entry and exit from outdoor spaces monitored using the new technologies. The experiment was conducted for 154 days on a commercial dairy farm located in Mantua (Italy) with 35 Holstein cows during the dry period. The availability of outdoor forage was monitored by mowing on several test plots, while meteorological conditions were monitored using a weather station. The cows were equipped with radio frequency identification (RFID) tags to record their free access to the pasture. Social interactions were monitored based on the temporal association of cow passages through the gate. To identify a leader-follower relationship, a kmeans algorithm was applied to log the frequency of time intervals between successive passages. Correlation analysis results between the number of daily passes and rumination and feeding time revealed strong correlations, with R² values of 0.71*** and 0.65***, respectively. Temperature-humidity index (THI) was the most influential parameter, while RH, solar radiation and rainfall appeared to have less significant impact. However, wind speed during the day and humidity at night have the greatest negative influence. The dynamic social network analysis (SNA) showed that the 42% of passages were associated with a leader-follower relationship and three key findings were observed: i) the cow established preferential relationships with specific members of the herd independently of animal's status (heifer or dry), age, and number of calvings; ii) some individuals are more skilled at establishing connections, while others tend to be more solitary; iii) when a significant bond is lost, it is often replaced by another.