Cortisol response of restricted suckling or artificially milk-feeding to a short-term emotional stressor in dairy calves and their dams

Abstract

AbstractThe present study examines the plasma cortisol reaction of suckling and non-suckling calves and their dams to short-term emotional stressors. Twenty six cow-calf pairs were randomly allocated into one of two treatments: restricted suckling (R) or artificially milk-fed (A). On the day of weaning, blood samples were taken to determine the basal cortisol level in the calves' home-pen. Immediately, calves from both groups were moved to an unfamiliar surrounding and isolated. After sampling cows were then moved to a trimming pen, and restrained for three hours. Higher cortisol concentrations were found in A-calves in comparison with R-calves starting 90 min post-isolation through until the end of the experiment (90 min later). A significant increase was detected 60 min post-isolation in A-calves, with highest values averaging 29.22 ± 7.27 ng ml–1, decreasing to basal levels 130 min later. In cows, no difference in serum cortisol concentration was found either between treatments or over time. It was concluded that calves allowed to suckle react to a short-term emotional stressor with less plasma cortisol concentration than artificially reared calves.