For farmers in New Zealand, Ireland and Australia, group feeding from Day 1 is normal.
In fact, we're pretty sure we've never seen an individual system in any of these countries!
Calves are born in the spring so there is a large volume of calves in a short time to make grouping of calves the same age an easy task.
There are many benefits to group feeding, most significantly the reduction of time, labour, and the improvements in calf behaviour. Cross suckling can be a barrier to group feeding, however there is a simple fix, slow the milk flow, regulate the intake and calves stop cross suckling!
A lot of study is being done around the benefits of group feeding.
A study at the University of British Columbia found that pair-housed calves continued to gain weight after weaning while individually housed calves experienced a lag in weight gain after weaning. Group or pair-housed calves also experience group learning. In a study performed at Utah State University, calves housed in groups learned to eat calf starter at an earlier age than calves housed individually. Consumption of calf starter promotes rumen development to increase feed efficiency.