Early Calf Separation from Cow Leads to Different Social Life30 April 2015
Cows and calves are often separated only a few hours after birth to help improve dairy productivity. However, such separations can have long-term effects on social behaviour when the calf grows up.
"Research has shown that the early social environment affects behaviour, stress reactivity and the ability to cope with different challenges in various animal species," said researcher Susanne Waiblinger from the Vetmundi Vienna.
Ms Waiblinger and her colleagues previously showed that rearing with maternal contact gives rise to adults with higher social competence.
They then moved on to look at the effects of different calf rearing practices on adult animal behaviour.
After dairy cows and their calves are separated, the calves are then fed milk or milk substitute via bucket or from an automatic feeder, and the calves and cows are therefore unable to form a relationship. After a few days or weeks in single housing, the young animals are usually transferred to a calf group.
The researchers examined a total of 26 differently reared cows.
Eleven animals were separated from their mothers immediately after birth before entering the calf group and being fed milk via automatic feeder.
The remaining 15 calves were kept with their mothers in the calving pen for the first five days and were able to establish a mother-calf bond during this time.
These 15 calves were then also moved to the calf area, but continued to have contact with their mothers. Nine of these calves were allowed access to their mothers twice a day, while the remaining six were able to move between the calf group and the cow herd at all times.
The scientists performed different tests once the animals had grown up to determine whether the different rearing strategies had a long-term effect on the behaviour of the animals in stress situations.
"Cattle are herd animals. As expected, all animals, whether they were reared with or without mothers, produced higher levels of the stress hormone cortisol when being isolated from the herd," Ms Waiblinger explained.
Cattle which grew up with their mothers expressed the highest levels of cortisol during isolation, but the heart rate measured in these animals was the lowest.
Ms Waiblinger continued: "These are fundamentally different reaction types. Some animals respond to stress situations with an increased heart rate, others produce cortisol.
"It is possible that the different rearing treatments result in different reaction types."
Differences could also be seen in the animals' behaviour.
Calves reared with their mothers, especially those who had constant maternal contact as well as contact to the herd, were more active during isolation: they moved more in their calving boxes and explored their surroundings more actively than cattle reared without their mothers.
This could indicate a higher level of motivation to rejoin the herd and a more active way to cope with the challenge of isolation, showing that these animals may be more sociable as adults due to their enriched upbringing.
Mother-bonded rearing of dairy calves is already in use at a number of farms.
"In the future, we must increasingly consider whether a socially restricted early environment represents the ideal form of animal husbandry," Ms Waiblinger argued.
You can view the full report and author list by clicking here.