Effect of a difficult calving on the vigour of the calf, the onset of maternal behaviour, and some behavioural indicators of pain in the dam.

The neonate's development and survival is dependent upon being vigorous at birth and receiving appropriate maternal care. However, difficulty at delivery can result in less vigorous offspring and maternal care can be altered, probably as a consequence of exhaustion, pain and human intervention. The first 3h after expulsion of the calf were observed continuously from videos following twelve natural calvings and sixteen calvings assisted by farm staff (including four malpresentations) from Holstein cows. Calvings were balanced within groups for parity of the dam, genetic group, sex and birth weight of the calf, calving pen and calving season. Assisted calves were less vigorous with higher latencies to attempt to stand, achieve standing, walk and reach the udder than unassisted calves (P<0.05). Furthermore, assisted calves also tended to be less likely to stand and walk within the first 3h after birth (P<0.1), spent more time lying on their flank (P=0.019) and had more frequent bouts of this behaviour (P=0.033). Assisted dams did not take longer to lick the calf and performed as much licking as unassisted dams (P>0.05), indicating no delayed onset or impaired expression of maternal behaviour in dams given assistance at delivery. Study of potential pain-related behaviours revealed that assisted dams spent less time self-grooming (P=0.033) than dams delivering naturally, which could suggest greater pain. However, there were no significant differences in any of the other pain-related behaviours. Our results suggest that, although maternal behaviour was unaffected by a difficult delivery, dairy calves born following difficult calvings have lower vigour in the first 3h after birth than unassisted calves. This might have longer-term effects on the health and survival of the calves.