Happy Birthday puppies

I'm wondering how big those ear tags are to contain all that data! Or do they just have a bar code and "somebody" transmits everything to a program via smart-phone? And then the sorting, ie: (1)these lambs are staying, (2) those lambs are going, and how to get the groups separated? I think I'd have the local 4-H club out for some free real life farming experience. :B

p.s. How are the pups doing?