All my chicks hatched except 3 and those 3 were all from the same hen (none of hers hatched - she is a DK Cornish) 2 never pipped and 1 pipped but never made progress. I opened the egg and found an unabsorbed yolk - what causes this and could I have prevented it from happening? (I'm thinking there isn't anything I could have done since nothing changed from the beginning to end of lockdown and the other 14 were fine)
