i have 4 plymouth barred rock who were laying in december 3 eggs a day, i added 8 more Lohman pullets about 18 weeks old, there was some pecking order battles going on from the plymouth rocks in that the Lohmans were having a problem getting to the food. but now the plymouths have not laid an egg in 2 weeks. there is lots of feed,lots of water, lots of room over 6 feet per bird, i give them some treats like corn or mixed grain most days but still no eggs from the plymouths, the Lohmans are starting to lay as their eggs are deeper brown and small.. any ideas??