Weaning and separation in two steps—A way to decrease stress in dairy calves suckled by foster cows

The aim of this study was to investigate whether the prevention of suckling and the separation from a foster cow in two steps lower the behavioural and physiological stress reaction in calves compared with if the two events occur simultaneously. Twelve groups, each consisting of one cow and four calves, were formed when the calves were 1 week old, and the calves were prevented from suckling at 10 weeks of age. In six of the groups, the calves were prevented from suckling by simultaneous separation from the cow (control). In the other six groups, the calves were fitted with a nose-flap, which prevented them from suckling while they were kept together with the cow for another 2 weeks before they were separated at 12 weeks of age (two-step). The behaviour and the heart rate of the calves were recorded, and saliva cortisol samples were taken after the calves were prevented from suckling (both treatments), as well as after the two-step separation. The two-step calves vocalised and walked significantly less when prevented from suckling than control calves ( p p p p p p