Licking and agonistic interactions in grazing dairy cows as indicators of preferential companies

摘要

The quality of the social environment should be studied as one of the welfare components of dairy herds. Licking and preference between cows are important socio-positive experiences in this context.The aims of this study were: 1) to describe the behaviours temporally associated with social licking in grazing dairy cows, 2) to measure the association of social licking with social hierarchy and gestational state and 3) to compare social licking between preferred mates - cows that are more often in close proximity - and other mates. Six commercial Jersey herds, averaging 24.6 +/- 5 lactating cows per herd, and managed on a rotational grazing system year-round, were enrolled in the study. Herds were kept constant for at least 30 d before data collection, and at four days before data collection the herds were habituated to the data collection routine. The behaviours of all cows within each herd were observed through direct observation for six days between milking, from 8:00 am to 3:00 pm. A total of 148 cows were observed for 42 h each during the study period. Licking events and agonistic interactions were observed continuously, and the individual instigator and receptor participating in each event were recorded. All agonistic interactions were registered, and a sociometric matrix was developed for each herd. Scan sampling (every 6-min) was used to register behaviours of each individual cow and its closest neighbours. Licking was a widespread behaviour in the studied herds, registered in 94.5 % of the cows and occurring most often around 10:00, during ingestive behaviours. Social lickings were most often observed immediately before drinking or mineralizing, and immediately after idling or ruminating. Social hierarchy was not associated with the number of social lickings. Pregnant cows received 1.63 more lickings than non-pregnant cows but didn't perform more. Furthermore, older cows performed and received more lickings than primiparous cows. Social licking interactions were higher (1.89 vs. 0.62; p <= 0.01) between preferential mates than the average for the herd. Similarly, agonistic interactions between preferential mates was higher (1.97 vs. 1.52; p <= 0.01) than observed among the average herd. Our results reveal that social licking is widespread among herds and suggests an association with social preferences when cows are on pasture, which may be related to affinity among cows. Preferred mates also showed greater number of agonistic interactions.