Suckling, weaning, and the development of oral behaviours in dairy calves

Dairy calves are generally separated from their dam at birth. They express non-nutritive oral activities such as licking or sucking other calves or objects, nibbling, or tongue-playing, which have been related to the absence of sucking a teat and ingestive chewing. We hypothesized that the dam, by its presence, can help focus the oral behaviour of calves towards nutritive activities and thereby limit the development of non-nutritive oral activities. To test this hypothesis, we compared calves suckled by their dam against calves separated from their dam at birth and fed milk through a teat (automatic milk feeder). Cow and calf behaviour was observed before weaning and after weaning at 10wk of age. Before weaning, the suckled calves were less active than the artificially fed calves. After weaning, suckled calves tended to spend less time on non-nutritive oral activities than non-suckled calves. Before weaning, suckling cows and non-suckling cows showed similar behaviour. Both cows and calves reacted to weaning: cows showed vocalization and agitation, and calves showed increased blood cortisol levels. We conclude that keeping dairy calves with their dam for 10wk can be beneficial to calves, although weaning induces a degree of stress.