I've got a Cuckoo Maran Roo that we rescued from a Ladie's canning project, we had a mixture of eggs under our broody hen and this is what came out of a RIR egg:
She also had 2 little buff minorca/cuckoo maran babies hatch out but sadly one of my other hens jumped into the nesting box and laid down, her leg crushed the neck of one of those babies. There are 2 more about to hatch out and five more eggs are pipped!
This hen went broody while I was in bed with a high fever and flu, my husband forgot that I wanted to stick my guinea eggs under her so we've got new chicks instead of new guineas LOL
Michelle

She also had 2 little buff minorca/cuckoo maran babies hatch out but sadly one of my other hens jumped into the nesting box and laid down, her leg crushed the neck of one of those babies. There are 2 more about to hatch out and five more eggs are pipped!
This hen went broody while I was in bed with a high fever and flu, my husband forgot that I wanted to stick my guinea eggs under her so we've got new chicks instead of new guineas LOL
Michelle