Is dairy calves grazing behaviour influenced by cow-calf contact experience?

Summary

Cow-calf contact is encouraged in organic dairy systems and increasingly requested by consumers nowadays. Rearing dairy calves with their mothers can teach calves how to graze and optimise grass use, as well as improve their welfare and growth. In the present study, we tested the short-term effects of cow-calf contact experience on the grazing behaviour of three groups of eight calves during their first two grazing days after weaning. ‘Dam’ calves (D) were reared and grazed with their mothers until weaning. ‘Mixed’ calves (M) were separated from their mothers after three weeks, thus experiencing cow-calf contact but not at pasture. ‘Control’ calves (C) had never experienced mother’s contact (separated at birth) or grazing. All calves started grazing on three similar plots offering heterogeneous vegetation. Scan sampling of calves’ activities were performed every 5 min, 6 hours per day (9h-12h and 14h-17h). Proportion of time spent grazing, ruminating and idling were calculated. In addition, for all these activities, the proportion of time calves spent isolated and lying was also calculated. When grazing, observers classified the type of grass chosen by calves (green or dry). Once turned out to pasture, calves from the three groups spent between 55 and 60 % of their daily time grazing; D-calves started grazing immediately (1 ± 4.6 min) unlike M- and C-calves (39 ± 4.6 and 23 ± 4.6 min). The day they were turned out to pasture (Day0), M- and C-calves grazed more dry patches than D-calves. Finally, these differences in behaviour between the three groups were mainly observed on Day0 and disappeared the following day. Consequences on calf’s welfare and growth should be further investigated in the long term.