When exporting data to a society the Primary ID is showing instead of the Society ID, which is entered differently to the Primary ID.
In Stockbook go to Setup > Society Details.
Check that the box "Tick this box if you use Society Ids. as your on-farm tags" is NOT ticked if your Society Id's are not used as your on farm tags.
This will only export the society ID, you will need to make sure all animals have society ID's entered.