PSV-2 An exploration of sociality among pre-weaned beef calves

Abstract

Abstract Preferential relationships have been reported between individual cows within a herd. However, less is known about the ontogeny of preferential relationships between calves and subsequent bonding behavior. The objective of this study was to characterize these relationships in pre-weaned beef calves, with the hypothesis that calves form preferential relationships with one another prior to weaning. Ten weeks prior to commencing formal observations, forty mature Angus cows and their calves were randomly selected from a research herd, balanced for calf sex and allocated to one of two grazing paddocks approximately 12 acres in size. Two weeks prior to weaning, direct observations of calf behavior were performed over period of 12 days, using instantaneous scan sampling between 0700-1230h or 1300-1830h, resulting in 6 scans per calf/day X 12 days (72 scans/calf). For each calf, the identity and proximity (in calf lengths) of the calf in closest proximity (aka nearest neighbor) was noted, as well as behavior. The ethogram included calf behavior (grazing, nursing, lying, drinking, locomotion, social contact and standing idle), and sociality was categorized as being within 5 calf lengths of another calf. Sociality was observed in 60% of all scans, and sociality of individual calves ranged from 47% to 72% of the scans observed (72 scans/calf). The statistical model investigating sociality included calf sex and the interaction of day and paddock. Sociality was equally likely in bulls and heifers (0.59 +/- 0.1; p=0.80). A significant day by paddock interaction was also identified (p=0.001), but no obvious trends were apparent. In conclusion, preliminary results provide support for individual differences in sociality of pre-weaned beef calves prior to weaning. Further analysis will explore if preferential relationships exist between individual calves, and how these might be associated with different behavioral states.