I got some BC Marans this spring from two different sources. There are about two weeks difference in ages. From the original 16, I am down to 9. A couple died in their first two weeks. I lost both roosters from each group at an early age and then about one a month with two in the last two days. They all have had the same symptoms. Lethargy, wing droop, and at times loss of coodination. Some that were sick earlier surprised me by recovering to only die later. I started them on medicated feed for about two weeks and then switched to organic starter. They feathered out beautifully and what has really bothered me is that it is the prettiest ones with the best color and leg feathering have been the ones to die. I always use DE and have supplemented with probiotics. They are on grass in a tractor. My older hens (not BC Marans) have not been ill, some of which I got from the same NPIP source as 11 Marans. Are Marans particularly susceptible to disease? I recently got some Welsummers that are doing great although they are adults. I thought it could be heat but they have shade and plenty of water. They have not been vaccinated. I have been trying to get help about vaccines but evrybody says no. What could it be?