The influence of social factors on allogrooming in cows

The influence of social factors on allogrooming is considered further in adult animals with stable social relationships. All occurrences of allogrooming behaviour were recorded in one dairy herd (Herd H) consisting of 20 Holstein cows and one beef breeding herd (Herd B) consisting of 25 Japanese Black cows housed at night in loose barns, during the 2 h before sunset for 54 days and 35 days, respectively. The effect of social factors on the time spent in allogrooming was investigated. In addition, spatial distribution of cows, which was affected by social bonds, was observed during grazing in order to investigate a relationship with allogrooming. Average time spent in allogrooming in Herd H and in Herd B were 20 s h^-1 and 45 s h^-1, respectively; this difference may have been partly a response to differences in social stability between the two herds. In Herd H, closeness in birth (familiarity) and kinship both had significant effects on time spent in allogrooming; dominance relationships did not have a significant effect. In Herd B, there were similar trends for effects of closeness in birth, kinship and dominance relationships, but none of these were significant. Allogrooming tended to be performed more between pairs which were close in birth date, among relatives and by subordinates on dominants. In addition, duration of allogrooming when housed was positively correlated with proximity during grazing. It is suggested that allogrooming in cows is an important behaviour pattern with functional significance for the formation and maintenance of social bonds, and the stabilization of social relationships, rather than being purely altruistic.