Most of mine that were dumped early were 1 or 2. One hen, who had been an excellent broody for Her first 3 years, had her 6 chicks leave her at 4 weeks.... seems like it was mutual. She hasn't gone broody since.I’m starting to wonder if there is a connection between the number of babies and how long mama keeps the babies? Also maybe the number of roosters who are continually fighting! We have 7 babies with either 4 or 5 of them being roosters.
Now that I think about it, most were cockerels.